WATER QUALITY OF THE BURIGANGA RIVER AND ITS IMPACT ON SURROUNDINGS AREA
1.1Introduction
Water is an important element for all living beings on this planet. It is needed not only for drinking, for growing food, for washing, but it is also important for many of the pleasant recreational aspects of life (Reeve, 2002). Water is one of the prime necessities of life. We can hardly live for a few days without water (Kudesia, 1990). It has become an essential commodity for the development of industries and agriculture (Kudesia, 1990). All life forms of earth depend upon water. Each human being needs to consume several litres of water daily to sustain his or her life (Baird, 1999). No life can exist without water since water is as essential for life as air is. Water is absolutely essential not only for survival of human beings, but also for animals, plants and all other living things (Raj, 1997).
Generally water contains iron, calcium, magnesium, manganese, silica, fluride, nitrate, phosphates, sulphates and chlorides (Kudesia, 1990). When the quantity of these parts increase then they affect the body system and cause destruction of health (Kudesia, 1990).
Arsenic salts can create cancer, cadmium affects kidney while barium carbonates has bad effects on veins, nerves and hearts. If the quantity of iron exceeds 30 mg/l then vomiting starts. Silver containing water causes liver and lung diseases (Kudesia, 1990). Excess of fluoride affects teeth and causes a disease called ‘Fluorosis’. The presence of manganese in water causes loss of memory, impotence and eye diseases. Vanadium spoils the fertility of the soil and creates cancer in the body while beryllium gives inflammation of pulmonary tissue (Kudesia, 1990).
When man and other higher animals began their life on this earth, there was absolutely no sign of pollution. There was perfect balance in various natural processes. The air and water was pure and soil was fertile. The problem of pollution arose with the very civilization of man. As soon as man learned to use fire, the air pollution began. As human pollution increased, there was increased in our working sphere and with this also increased the pollution (Trivedi, 1992). To day, the cry of “Pollution” is heard from all the nooks and corners of the globe, and pollution has become a major threat to the very existence of mankind on this earth (Trivedi, 1992).
Pollution of water may be by different sources, soil erosion in the catchments of rivers, streams and ponds leads to excessive sediments load thus polluting the water system (Trivedi, 1992). Streams and other water systems are also polluted by municipal waste and industrial effluent, particularly the responsibilities for maintaining civil amenities like water supply, drainage, slum, clearance, open and streets in the rests with our municipal bodies. Unfortunately there has been a dismal failure on the part of our municipal bodies to keep the cities and near by streams clean (Trivedi, 1992).
Man has fried to cope with this scenario and has rapidly advanced his efforts to counteract this malady. In past few decades natural and polluted water have been studied in detail all over the world and considerable data are available on most kinds of pollutant and their effects on ecosystems as well as on organisms but when one look to the observation of sewage water qualities which includes the sludges, one finds that is essential to have a regular monitoring of the qualities of the river water which becomes the basin of sewage water. The defilement of water as a result of human activities is a phenomenon as old as the increasing industrialization, urbanization and development activities and consequent pollution of water has brought a veritable water crisis. Today most of the rivers of world receive millions of litre of sewage, domestic waste, industrial and agricultural effluents containing substances varying in characteristics from simple nutrients to highly toxic substances (Trivedi, 1992).
We have still to recognize that good environment is the fundamental right of every citizen as it is essential for his physical, moral and social health. The problem of pollution continues to pose as serious a challenge as the threat of nuclear war (Kudesia, 1990).
Many fresh water resources are contaminate through human activities. Many millions more suffer from frequent and debilitating water-borne illness. About half of the inhabitants of developing countries do not access to safe drinking water and 75% have no sanitation, some of their wastes eventually contaminating their drinking supply. As well as causing much suffering, water-borne diseases also result in great economic loss (Mason, 1996). Water pollution has proven to be a very serious and very visible form of environmental contamination (Francis, 1994). Now a days river are used indiscriminately as dumps. The River Buriganga which is choked with industrial effluent and untreated sewage through numerous outfalls (Khan, 1199). Only one half of the urban population has access to reasonably safe waters; the remaining half depends on contaminated traditional sources. As a World Bank report of 1996 notes, the quantity of water produced per capita in the Greater Dhaka City has not kept pace with the rapid population growth (Khan 1999).
Untreated and waste waters generated in urban centres, industrial establishments etc. advertently or inadvertently are deposed of into the surface bodies which pollute them to such an extent that they become unfit for the designated use (Agrawal, 1994). Such waste water, if processed, can be recycled for use in low grade designated we like flushing of toilets, horticulture, cooling water requirement etc (Agrawal, 1994).
The need for wastewater treatment in developing countries can be seen in the numerous instances where raw sewage is diverted into streams or oceans, thus contaminating water that could be used for human consumption, industrial needs, land irrigation, fish production or recreation (Canter et. al., 1982). However only a small percentage of the population in most developing countries is served by waste water treatment processes, the lake of qualified personnel to operate and maintain sophisticated treatment processes, and the low priority generally assigned to waste water treatment relative to other national needs (Canter et. al., 1982).On the above discussions, all should be concerned about the polluted water of the Buriganga River. The authorities will have to chalk out for treating the water of Buriganga River. Not only the authorities but also all peoples have to be careful about the river.
1.2 Rational of the Study
Safe environment is the precondition of safe life. But now our environment is being polluted with alarming rate. The scientists all over the world are searching the causes of water pollution, sources of water pollution and trying to find out the ways to prevent the environment from pollution.
There are some elements of our environment which are important for a safe environment. Water is one of important elements of our environment. It is also equally important for our life. Without fresh water life can not survive even a single moment. Not only for human life but also for agricultural, industrial, domestic and commercial uses, quality water is needed.
Now a day, to conserve environmental balance people from the different corner of the earth are very conscious, scientists are trying to find out the causes of environmental pollution, trying to find out the intensity of pollution and trying to find out the preventive measures. There was held a seminar headlined “Bangladesh Environmental Management” at Bangladesh University of Engineering and Technology (BUET) in 1989 and drew some directions. Raising awareness of common people for realizing the effect of polluted environment was the main direction of that seminar on that day. So, to protect the environment degradation, first of all people’s awareness is needed. It is hopeful that the present research headlined “Water pollution of Buriganga River and its impact on surroundings” will help to raise awareness and will help to be careful about our environment.
A survey conducted in 1998 by the Department of Environment (DoE) showed that the river flowing by the capital’s western flank had been boxed in by at least 244 establishments, most of which are makeshift homes, small factories, dockyards, boat making workshops etc. The survey revealed that approximately 50 acres of Buriganga land have been encroached upon by those occupants. It is strongly desired that the present research will convey much information’s about encroachments which will help to understand pollution.
Water of the Buriganga River turned septic under the huge burden of effluents flowing into it, mostly coming from the sewerage system and caring chromium-rich leftovers from the tanneries at the city’s Hazaribag area. The river with black and stinking water, is constantly receiving industrial and other toxics and poisonous wastes of Dhaka city and oil and grease spill from riverine vessels. Its water is no Langer clean and transparent. Today, the living organisms in the river from Mirpur to Bangladesh-China Friendship Bridge point are all dead, according to a Department of Environment (DoE) survey. The dissolved oxygen in water near the Hazaribag point, according to the survey, reached at a low of 2 mg/litre during January-May period (Chowdhury, 1999). From above statement it is cleared about the quality of water of Buriganga River. For these reason, by taking consideration on water quality of Buriganga River, the selected research topics is logical and time worthy. The present research will help with a great extent to investigate the deteriorating quality of Buriganga River.
Though a few researches were conducted by various organizations, but the present research will provide further data and information to realize the present condition of water quality which was ignored in previous researches.
1.3 Objectives of the Study
River is an important resource for mankind. Today’s industries dump all their waste whether solid or liquid into water (Sharma, 1994). The industry does it because it is the cheapest way to dispose off their unwanted waste. This is in spite of the fact that the law prohibits such dumping. The water of Buriganga River is being polluted through many ways. Polluted water contains many kinds of chemicals and other harmful products spoil the soil, plants and aquatic life and through various sources they enter into man’s body causing number of disorders in various parts and even cancer (Kudsia, 1990). Therefore, in order to ensure the sufficient quantity of good quality water for the peoples of adjoining area, all should be known to the water of the Buriganga River. To meet up the necessary requirements several specific objectives has been taken which are as follows:
1. To observe the changing scenario of various parameters of water in Buriganga River;
2. To find out the sources and extent of pollution;
3. To determine the impact of sewage and other waste waters on Buriganga River;
4. To improve water quality by setting standards for water treatment; and
5. To assess the effect of polluted water on its adjoining area.
1.4 Literature Review
Andrews (1972) examined on environmental pollution. The study was designed to increase awareness of environmental problems and full comprehension of the cause and effects of environmental pollution. This study is very relevant to my research.
Reid (1982) reveals appropriate methods of treating water and waste water in developing countries. Here, he explained the importance of water and waste treatment to development of the second and third worlds.
Sarwar (1987) examined some aspect of pollution of drinking water in Dhaka city. He worked to find out the existing situation of water supply of Dhaka city and problems of pollution relating to it.
Stumm (1987) emphasized on chemical processes occurring at the interfaces of water with natural occurring solids. The processes discussed and the concepts presented are applicable to all natural waters (oceans and fresh waters as well as soil water systems and sediment water systems) and to the surfaces of natural solids such as minerals, soils, sediments, biota and humus.
Shamsuddin and Alam (1988) examined on significant variation in water properties between the non-industrial and the industrial sections of the Sitalakhya River and they found significant differences between the industrial and the non industrial stretches in both dry and wet seasons and hence, provide an indication of the extent of pollution in the industrial section.
Siddiqui (1989) examined about fresh water pollution and he categorized the use of fresh water such as i) Irrigation ii) Industry, and iii) Public use etc. As a result the earth’s resources continue to be severely taxed, resulting serious degradation of water quality.
Kudesia (1990) explained sources and nature of various types of industrial effluents and their constituents which are discharged by the industries. He revealed the various techniques involved in collection, preservation and tabulation of industrial samples. He further examined on water pollution principles of disinfection of drinking water, sanitary technology in environmental conditions of our subcontinent. It reveals a comprehensive account of the mechanisms involved in purification of drinking water with various oxidizing disinfectants. It also explains the possible measures to be adopted for controlling the problem of water pollution.
Hasbam (1990) has examined on river pollution. He tried to reveal the awareness of its damaging effects to the rivers and the life they contain, to the seas to which the river flow and on the people drinking the water, is spreading.
Kudesia (1990) worked on pollution and revealed that, various types of pollution occurring in man’s life due to interference with nature. These various sources of pollution have caused mental order, skin ailments, stomach, diseases, blindness and genetic changes; he also explained the techniques for the detection of pollutants have been described in very lucid style so that a common man may understand them.
Trivedy (1990) examined on river water pollution. He revealed that pollution of a river first affects its chemical quality and them systematically destroys the community the delicate food web Diverse use of the river are seriously impaired due to pollution and even the polluters like industry suffer due to increased pollution of the river.
Trivedi (1992) reveals various problems related to the deterioration of man’s natural environment are through industrialization and urbanization of his mode of life including the danger of genetic degeneration of making himself.
Swarup (1992) studied on water pollution nature and Importance, of water pollution, municipal sewage treatment, Industrial waste etc.
Hossain and Saha (1993) revealed that during dry season (starting from December to March), most of leaves started to shed while a few vegetative buds unfolded. Flowering and fruiting of jackfruit trees start from november and continue up to mid April. Because of the temporary deciduous nature of the angiospermic parasites, they apparently looked to be almost dead by the end of March. By mid April they started a new life by producing numerous vegetative buds and unfolding young leaves, which continued up to the end of May. The growing period and shining yellowish-green color luxuriance persisted up to the end of July. Vegetative growth of the parasites began to cease by mid-August and during this time, older leaves lost their shining color, started to become a bit blackish and ultimately fell off from the plant body. Flower buds appeared in great numbers. Flowering, pollination (by bird) and fruiting were also recorded in some of the parasites during November to December, particularly in macrosolen cochinensis.
Socolow (1994) revealed a wide-ranging exploration of this approach to environmental problems. With contributions from a broad range of disciplines-environmental science technology assessment, economics, policy studies, the book lays out the range of concerns encompassed by industrial ecology.
Agrawal (1994) studied on 29 Indian rivers which reveals, all river water is unfit for human from human settlements account for four times as much as industrial effluents.
Sharma (1994) examined water pollution and pollution control acts, regulations. He has further discussed on pollution problem areas, pollution auditing of a plant global environmental essays etc.
Wahiduzzaman (1994) revealed an impact of textile to pollute the water of Sitalakhya. River various pollutants were discussed here to reach at the objectives.
BBS (1994) survived by agriculture census project. It’s running works in 1889 and its aim on internal fish cultivation identification. Finally it was three types that are fish cultivation, reject and under cultivation.
Bhuiya, et. al. (1994) investigated the sample eco map of Dhaka city surface water bodies. Fifty water samples from different water bodies were drawn for parametric tests and measurements revealing physical and chemical characteristics of water quality or pollution vector. Parametric values have been obtained for the determinants of water quality of pollution viz. Temperature, hardness, turbidity, CO2, pH, DO and BOD. The physical and chemical characteristics of water samples are determined by the methods of American Public Health Association.
Hounslow (1995) interrelated water analysis or a group of analyses with major applications on ground water pollution or contaminant transport.
Hounslow (1995) examined on water quality data to help bridge the gap between “Standard” geology and geochemistry and the present job requirements of hydrologists in their evaluation of various water-pollution scenarios.
Manivasakham (1995) examined to fulfill the need for a simple and concise manual on the computed physical & chemical examination of water, sewage and industrial effluents. Every effort has been made to present the material as simply and clearly as possible. Each and every determination are provided with chemical equations on which the colorimetric /titrimetric procedure is bases. The section “Interpretation of the result “enables him to know the limits, effects and other aspects regarding each constituent present in water and waste water.
Billah, et. al. (1995) compared the status of trace elements in drinking water of Jahangirnagar University Campus with water standard quality as per WHO specifications. The implication of the results is also discussed. The concentration of the trace elements in drinking water supplies in JU Campus is found lower than the maximum permissible level except those for Pb and Cd. The high concentrations of Pb and Cd may be due to geomorphological differences between JU Campus and Dhaka which is about 30 km away. These toxic elements may be removed from drinking water by standard procedures.
Schnoor (1996) examined on environmental modeling. The objective of his attempt is to demonstrate, how to develop and solve mathematical models for a wide variety of chemical pollutants. The emphasis is on natural water.
Khan, et .al. (1996) studied on sewage pollution in Chittagong Metropoliton Area. They found that all the parameters of the sewage discharged in the canals such as Chemical Oxygen Demand (COD), Biological Oxygen Demand (BoD) etc. fluctuated substantially. Dissolved oxygen (Do) was always remarkably low.
Rahman (1996) examined on the perception of water quality in Khulna. He worked to demonstrate people’s ability to identify and to perceive the quality of water that they generally use for livelihood. To find this he surveys a questionnaire survey in the Khulna city.
Chnabra (1996) examined on soil salinity and water quality. He deals with the emerging issues of environmental degradation, especially the methodologies to put to productive uses urban and industrial waste waters.
Schnoor (1996) has examined environmental modeling, the objective of the study is to demonstrate how to develop and solve mathematical models for a wide variety of chemical pollutants. The emphasis is natural water.
Alam, et. al. (1997) investigated the effects of pollutants of Zia Fertilizer Factory discharged into the river water of the Meghna. They found that the values, however, are well within the allowable values both in the dry season and rainy season and rainy season.
Pavel, et. al. (1997) reveals that the soil was clay to loamy and was composed of 29.425% sand, 38.075% clay and 32.50% silt. The CEC was recorded as 13.74 meq/100g. Different physico-chemical properties of soil i.e., pH, OC, avail-N, avail-P and Exg-Ca were determined and were found to vary from 6.3 to 7.2, 0.52 to 0.78%, 9.5 to 13.00 ppm, 6.25 to 18.50 ppm and 65.85 to 95.35 mg/100g of soil respectively. The observation of the study indicates that the experimental pond was in a favorable condition for fish culture.
Farmer (1997) revealed a “Classic” media-bases approach to examining pollution issues, i.e. by undertaking a separate consideration of air, freshwater, marine and radioactive substances. This approach is in effect, bucking the trend of integrating pollution management.
Giriappa (1997) has studied on rational water use that is gaining increasing importance during recent years in the management of modern agriculture. As irrigation is prerequisite for the use and achieving optimum results from the modern farm inputs, the study on water management in this context gains importance.
In the study “Dhaka City Storm Water Quality Assessment”, Khan and Chowdhury (1998) described that the deterioration of storm water quality in Dhaka has become a matter of concern in the recent years. Identified as one of the most densely populated cities in the world, Dhaka is unable to provide urban quality of living to its over 6 million inhabitants. Much of this inability has resulted from failure to maintain the required water environment of the city.
Rahman, et. al. (2000) studied to investigate the effects of pollutants of the Jamuna Fertilizer Company Limited (JFCL) discharged into the river water of the Jamuna. The study shows that the pollutants in general had little effects on the river water.
Sultana and others (2000) investigated the water quality of Dhaka city lakes. They worked in the residential areas of Dhaka City there is a scarcity of open spaces but all four planned major residential areas are endowed with water bodies/lakes. Presence of lakes in the residential areas is an advantage as it enhances the beauty of the area, influences the microclimate with its cooling effect at night while the banks of the lakes are utilize for recreational purposes.
A project taken by Dhaka Water and Sewerage Authority (DWASA)(2000) on “Rehabilitation of Dholai Khal” described in its report that before 1947, storm water of Dhaka city drained out through different natural canals. But thereafter, the city developed spontaneously without any master plan causing depletion of natural drains. Henceforth water logging became a problem for the city. In 1964, Dholi khal was filled in for carrying out development works without taking any necessary steps to drain out the water of surrounding area and thus water logging turned out as a great problem.
Tareq and Rahman (2001) investigated the chemical and microbiological quality of potable water. The analytical results obtained indicated that there are considerable variations among the examined samples with respect to their chemical constituents which only occasionally fell above the maximum permissible levels of BSTI drinking water standards. Off all the water classes (DTW, HTW, TW) studied, the locally stored consumer level water showed the highest mean concentration for the ammonium (2.80-5.42 mg/l) and coliforms (210-890 cfu/100 ml). However the quality of water is satisfactory at their origin (i.e., DTW and HPTW), but at the consumers level (i.e., tap water; TW) is highly polluted with faecal coli forms, which may be attributed to the lack of proper management of water supply system.
A study named “Flood Management and Vulnerability of Dhaka City” done by Huq, et. al. in 2001. In their study “effect of urbanization on storm runoff characteristics of Dhaka City” investigated the impact of land use changes due to urbanization on storm runoff characteristics in the eastern part of Dhaka City. They found that the volume of peak rate runoff increases with growth in urbanization. Most of the low lying lands, which once acted as retarding basin, have been filled up. Computed results show that runoff volume is increasing with increase in built-up area in Dhaka City.
Reeve (2002) examined on environmental analysis. It is an introduction into how, sometimes familiar, at other times less familiar, chemical analytical techniques are applied to the environment.
Downs (2002) studied on monitoring ecological impacts it reveals the logic and ways may make strong inferences that lie behind the design of effective monitoring programs – those that allow detecting and assessing, with some confidence whether specified human activities are causing unacceptable changes to the environment.
Hussain (2003) identified the transformation of urban fringe wet lands eastern Dhaka City. She also studied the nature and process of urban fringe wetland transformation and its consequential effects. She observed that wetland at eastern part of Dhaka city has been transformed and drastic changes have been occurred in the permanent and seasonal wetland during at last ten years.
Alam (2003) described that after implementation of the flood control project in the Dhaka West, unplanned and uncontrolled expansion of urban area stretched rapidly toward the low-lying areas adjacent to the flood protection embankment. These are deeply flooded floodplain areas close to the river. The residents of the houses in these lowlands suffer from inundation due to accumulation of rainwater after heavy rainfall. Land development through land filling processes in the low-lying areas is causing a drastic reduction in water storage areas. Construction of embankments through low-lying areas without providing adequate drainage facilities has caused internal flooding adversely affecting the residents in those areas.
Ansari (2004) revealed there has been a changing trend in the land use feature over years hail hoar in the human ecological factors. This is happening mostly in the recent decades. The ecological hail hoar is disturbing. Loss at water bodies, water pollution, and introducing exotic species well as pest attract is losing biodiversity in the study area.
But at present it seems that the beauty spots of the residential areas have undergone drastic change, instead of being a healthy habitat for the residents the lakes have turned into highly polluted water bodies endangering the environment and the health of the residents. They compared with the water quality with the Bangladesh standard.
DOE had analyzed the suspended data of the Dhaka city different lakes, utilizing the data of 1990-2007. According their analysis the water quality of Dhaka city lakes clearly identified (DOE, 2007).
From the above discussion it can be said, there is a lot of works on the water pollution but there is no works on water pollution and its impact in selected study area. For this reason, this research is conducted and tried to investigate some objectives.
1.5 Organization of the Study
In first chapter there is discussed an introductory discussion on water pollution and its importance. There are also discussed on the significance of the present study and was set some objectives. Literature review was constructed in this chapter. The scope and limitations were discussed also in this chapter.
In the second chapter research methodology is discussed by which the present study is explored. Here it is discussed how to gather primary and secondary data which is related with the present study and various chemical regents are discussed also to find out the state of the water.
Chapter three is constructed on study area of the present research. There are discussed physiographic and geologic characteristics, soil characteristics, climatic characteristics and land uses of the study area.
Water pollution and pollutants are discussed in the chapter four. Sources of pollution and various pollutants which are mainly accused of water pollution are discussed in this chapter.
In chapter five various sources are discussed from where wastes are coming and mixing up with the water of the Buriganga River. The solid wastes are classified in to several types which are shown in this chapter.
Chapter six is reveals about the state of the water of the Buriganga River. Parameters of the water were collected from the Department of Environment is represented in this chapter. Collected samples were examined in the laboratory also represented here.
In chapter seven, collected information’s by questionnaire survey are analyzed. Three locations were selected for survey where 200 questionnaires were used to gather various information which are represented in this chapter, and in chapter eight findings, discussion and recommendation were made.
1.7 Scope and Limitations of the Study
The present study is constructed on water quality of Buriganga River and its impact on surroundings area. It’s on analytical representation and bases on secondary data specially. To analyze water quality some of parameters is selected and the present research is constructed after based on these parameters. Water pollution, various pollutants, sources of pollutants, prevention of pollutants, probable remedy of pollution, impacts of pollution on surrounding are of Buriganga river are included in the present study. At the same time to assess environmental condition, for there examination on geological condition, soil condition, drainage system, uses of river water etc are discussed in the present study.
Water of Buriganga River is a dependable source of water to the people of Dhaka city. But the present study will bring a preliminary conception about various sources of pollution existing in the study area. In spite of above advantages there are some limitations also. One of the major problems is data collection. Data collection is very difficult and expensive. To collect related data and sample test needs huge amount of money. So scarcity of money and scarcity of times limits the research scope. The present study is based on secondary data though primary data was collected. But the matter of fact all parameters could not obtain as it is very costly.
Besides all of these barriers the present study is very much informative and all selected objective was fulfilled. The present study will also be helpful to them who desire to further study in this sector.
2.1 Introduction
To extract real phenomena, research is most easiest and traditional systems. Several procedures are needed to complete any research. The ultimate result of a research depends on overall procedures. So adjustment between objective and procedures is an important issue. Generally research can be considered as a scientific process to get vast knowledge about a certain thing.
Accurate and dependable information’s are needed for obtaining true knowledge about something. Data collection is the most important part to perform a research. For this reason in various researches, many types of data are colleted to meet up objectives.
There is a vast scope in geography and environment as a discipline, in geographical research man, nature; environment and spatial discrimination are priority full. In geographic research, research methodology is constructed after based on physical, social and economic situation of a certain area. For this reason different methodology are made for different places.
“Water pollution of Buriganga River and its impact on surrounding” is a title of present research which is conducted based on field data and secondary data. To perform the present research the following procedures were followed:
2.2 Data Sources
The research is based on both primary and secondary data. Primary data were collected through field work and on laboratory work and secondary data were colleted from various sources as detailed below (Table 2.1):
Table 2.1: Sources of data.
| Primary data | Secondary data |
| 1. Field work
2. Laboratory 3. Analysis of water samples |
Department of Environmental, Dhaka
Dhaka Municipal corporation Various published and unpublished materials. |
2.2.1 Map Collection
After selection of a study area maps and maps related information were collected. Maps were collected from various institutions such as Department of Environmental, RJUK, and the Department of Geography and Environmental of Jahanagirnagar University.
2.2.2 Book Review
Related information both published and unpublished, related with the present research were collected.
2.2.3Primary Data
To capture primary data direct field survey was made and to determine the pollution of the Buriganga River water sample was collected and a questionnaire survey was prepared at survey area.
2.2.4 Secondary data Collection
To fulfill the aims and objectives of the present study, the importance of secondary data are very essential. In this research secondary data were used which are generally published by various institutions and researchers. Various published and unpublished information’s, file, research paper and data were also used here. Moreover river water pollution and its impact related many books, published unpublished journal, the daily news paper were explored thoroughly. Major sources of secondary data from where secondary data were collected mostly are Department of Environment, Dhaka Municipal Corporation, Department of Geography and Environmental, Jahangirnagar University, Department of Environmental Science, Jahangirnagar University, Central library of Jahangirnagar University, Bangladesh water Development Board, Bangladesh University of Engineering and Technology are especially mentionable.
2.3 Analysis of primary Data
Samples were collected from the various point of the Buriganga River. These sample points were selected randomly.
Water samples were collected in about 1000 ml bottles and temperature of the water was taken on the spot. Collected samples were analyzed by the Department of Environmental Science, Jahangirnagar University and the Department of Chemistry, Jahangirnagar University. The seven parameters by which analysis was done were selected in accordance with water quality standard in Bangladesh as well as with the international standard. These standards refer to drinking, fishing, industrial uses, agricultural uses and recreational uses.
2.3.1 Numerical Presentation
Numeral presentations were made to represent the collected data because it helps to realize the main idea.
2.3.2 Graphical Presentation
The result was presented by graphical diagram. That helps to realize the result of the study which is presented with vertical graph and circular graph.
The methodology developed to perform selected objectives which are given below as a flow chart (Flow chart 2.1):
Flow Chart 2.1: Methodology of the present research.
2.4 Water Quality Measurement
Three primary factors are necessary to determine the water quality. These are sampling techniques, analytical procedures, and units of expression. Misunderstanding and misinterpretation of data is feasible when these factors are not clearly understood. Two of these are discussed as follows:
2.4.1 Sampling Techniques
To analyze the water quality of the Buriganga River samples were collected. Experiments were carried on the collected water sample to determine the physical, chemical and the biological aspects of the water. Physical examination was conducted to find out the color, conductivity, temperature and odor. Chemical examination revealed the total solids/dissolved solids in the water and the pH component of the water. Biological examination determined the dissolved oxygen of the water.
2.4.2 Analytical Procedures
pH of the water samples were measured at field by using digital pH meter ( SCOTTOH GERATE, Gmh, CG 818). Dissolved Solids & suspended solids were determined gravimetrically according to procedures given by USPA and vesilind in the Laboratory and following instruments were used in the laboratory (Table2.2).
Table 2.2: Instruments used in the laboratory.
| Parameters | Instruments |
| pH | Microprocessor pH meter, Model No- 211, Hanna instrument |
| Specific Electric
Conductivity |
Conductivity meter, Model No- HI 8633, Hanna instrument |
| Salinity | Conductivity meter, Model No- HI 8633, Hanna instrument |
| Dissolved Oxygen | Dissolved Oxygen Meter, Model No-9143, Hanna Instrument |
| TDS
(Total Dissolved solid) |
Total Dissolved Solid meter, Model No- HI 8734, Hanna Instrument |
| Turbidity | Microprocessor Turbidity Meter. Model No- HI93703, Hanna Instrument |
2.4.3 Determination of Water Temperature
The temperature was taken by a mercury thermometer graduated 0ºC to 100ºC. From the water sample was taken in a clean beaker and bulb of the thermometer was dipped into the water for one minute. The mercury of the bulb was gradually raised through the uniform bore of the stem and become stationary at a certain point. A fine remark was put on the stem of the thermometer at the position where top of the mercury become stationary. The value was noted and repeated the procedure three times in the sample. The mean value was the water temperature.
2.4.4 pH Determination
The pH of water sample was determined by using a glass electrode pH meter (Griffin pH meter, model No.40). The pH meter was calibrated with two known buffer solutions (pH 4.0 and 9.2). Then the electrode was rinsed thoroughly by using distilled water and wiped by using tissue paper. The electrode was dipped into the sample water and was kept until the stable reading was observed. The final reading was recorded.
2.4.5 Dissolved Oxygen
Dissolved oxygen is probably the single most important chemical parameter that is required to ensure the ecological health of receiving water. It is frequently the key substance in determining the extent of kinds of life in a water body. Dissolved oxygen content of sample water was determined by using DO meter (HANNA INSTRUMENTS: HI9143, Dissolved Oxygen Meter, Portugal). The sample bottle (250 ml.) was completely filled up with water to avoid the existence of air and DO was measured just after the sample collection.
2.4.6 Biochemical Oxygen Demand (BOD)
Biological Oxygen Demand refers to the quantity of oxygen required by bacteria and other microorganisms in biochemical degradation and transformation of organic matter under aerobic conditions. This quantity of oxygen is proportional to the degradable organic substances present and therefore it is possible to estimate from the BOD5 value the degree of water pollution. High BOD5 values indicate water pollution. BOD5 is an empirical, semi-quantitative method, based on oxidation of organic matter by suitable microorganisms during 5-day period. The basic principal underlying BOD determination is the measurement of the DO of sample that is utilized by suitable microorganisms during 5-day period.
The following reaction takes place,
Microorganism
CH2O + O2 CO2 + H 2O
i) Procedure
The collected sample was taken in a suitable bottle (250ml). The dissolved oxygen (DO) content of water (D1) was measured by using DO meter (HANNA INSTRUMENTS: HI9143. Dissolved oxygen meter, Portugal) before incubation. Then the bottle was sealed and incubated the dissolved oxygen (DO) of eater was measured by using DO meter.
ii) Calculation
The following formula was used to calculated the biological oxygen demand (BOD5) of water,
BOD5 (mg/l) = D1 – D2
Where,
D1 = Dissolved oxygen (DO) content water sample before incubation.
D2 = Dissolved oxygen (DO) content of water sample after incubation.
2.4.7 Determination of Chlorine Concentration
The best-known reaction for chloride determination is based on the formation of nearly insoluble silver salts.
Cl¯ + AgNO3 ® AgCl (white spongy ppt)
AgNO3 in the presence of the indicator K2CrO4, is used for precipitating chloride.
NaCl + AgNO3 ® AgCl +NaNO3
K2CrO4 +2AgNO3 Ag2CrO4 + 2KNO3
First of all, the most stable salt (AgCl) is formed and then the excessive AgNO3 reacts with K2CrO4, forming a reddish brown of AgCrO4, which indicate the end point of the reaction.
i) Apparatus
Burette, Pipette, Conical flask, Porcelain dish and shaking machine.
ii) Reagents
1. Potassium cromate indicator: 5%aqueous solution of pure K2CrO4.
2. 0.02N AgNO3 solution: Dissolved 3.4g of AgNO3 in double distilled water & make up to 1 liter. Standardize this solution against a standard NaCl solution and store in amber colored bottle away from light.
iii) Procedure
1. Take 5ml of filter water sample.
2. Add 5/6drops of K2CrO4 indicator and titrate the solution with 0.02N AgNO3 solution (with stirring) till the first reddish brown tinge appear. The volume of AgNO3 (titre blue) required refers to the amount of chloride present.
iv) Calculation
1 ml of 0.049 N AgNO3 = 1 mg of Cl¯
A × N ×1000
Therefore, Chloride (mg/l) =
0.049 × V
A = ml of the AgNO3 required.
N = Normality of the silver nitrate solution.
V = ml of the sample taken.
2.4.8 Determination Total Hardness
A compleximetric titration using EDTA is a classical method for determining Ca and Mg simultaneously or individually. Analytical success is based on eliminating possible interfering ions, achieving the required pH and employing the approximate indicator.
i) Reagents
1. Buffer solution of pH 10 (NH4Cl-NH4OH buffer).
2. Standard EDTA solution (0.02N): Primary standard disodium EDTA was used.
3. NH2OH.HCl solution: Dissolved in five gm of NH2OH.HCl in 100ml of distilled water.
4. K4Fe(CN6)solution: Dissolve 4gm of reagent grade potassium ferocyanide trihydrate {K4Fe(CN)6.3H2O}in 100ml of distilled water.
5. TEA reagent grade.
6. EBT indicator: Dissolved 02gm of EBT in 50ml of methanol. Prepare a fresh solution.
7. Calcon indicator: Dissolve 20ml of calcon in 50ml of methanol. Prepare a fresh a solution.
8. NaOH 10% solution: Dissolved 10gm of reagent grade NaOH in 90ml of distilled water.
ii) Procedure
1. Place 5ml of sample water and add 5ml buffer solution.
2. Add 10 drops of NH2OH,HCL, K2Fe(CN)6 respectively.
3. Add 5 drops of TEA.
4. Bring the solution to pH 10 by adding 15ml or larger quantities if needed, of the buffer solution. Heat the solution to near boiling for several minutes to speed the reaction.
5. When the solution has cooled, add 10drops of EBT indicator and titrate it from a blue to a red permanent color with the standard Ca solution.
iii) Calculation
1ml of 0.01M EDTA= 1mg CaCO3
Therefore,
A × M × 100000
Total hardness (mg CaCO3/l) =
V
A = ml of required Mg EDTA in titration.
M = Morality of the EDTA titrantion.
V = ml of the sample.
2.4.9 Determination Total Alkalinity
Hydroxide, Carbonate and Bicarbonate Alkalinity titremetric method (APHA, 1976) was used for determining total alkalinity. The estimation is based on the simple acidimetric titration. in the presence of phenolphthalein for CO3` (pH >8.5) and then in the presence of methyl orange for HCO3` (pH < 6.0).
When a mixture of carbonate and bicarbonate is titrated with standard H2SO4, the following reactions occurs-
NaCO3 +H2SO4 ® NaHSO4 + NaHCO3
2NaHCO3 + H2SO4 ® Na2SO4 + 2CO2 +2H2O
Phenolphthalein gives color so long as CO3` remains. It will discharged as soon as all the CO3` is converted into HCO3` . HCO3` can be titrated to neutrality with methyl orange as indicator. In the titration with methyl orange, the original HCO3` , together with the HCO3` found from the titration of CO3` , is neutralized by the standard acid.
i) Apparatus
1. Burette
2. Pipette
3. Conical flask
4. Porcelain disk
5. Shaking machine.
ii) Reagents
1. Phenolphthalein indicator: 0.25% solution in 60% ethyl alcohol.
2. Methyl orange indicator: 0.5% solution in 95% alcohol.
3. Standard H2SO4 (0.0925N).
iii) Procedure
10ml water sample was taken in a conical flask. Two drops of Phenolphthalein indicator was added to it. No pink color was formed which indicated the absence of hydroxide and carbonate alkalinity.
3.1 Introduction
Buriganga River is a tidal-influenced river passing through western and southern part of Dhaka city. In ancient times one course of the Ganges used to reach the Bay of Bengal through Dhaleshwari River. This course gradually shifted and ultimately lost its link with the main channel of the Ganges and was renamed as the Buriganga. The Buriganga River originated from the Dhaleshwari River. Its average width and depth are 400m and 10 m respectively. This river is only 27 km long (Banglapedia). The Turag has met with the Buriganga at Kamrangirchar of Dhaka city. However, the main flow of the Buriganga River comes from the Turag and it meets with the Dhaleshwari River at Munsiganj. The present head of the Buriganga near Chhaglakandi has silted up and opens only during floods, but the lower part is still open throughout the year. The Buriganga River has a great economic importance. It is used as an important water route through which people may go anywhere of Bangladesh by launch by boats etc. This river has been selected as study area (Fig.3.1) and the present study is performed from Mirpur Bridge to Pagla in this river (Fig.3.2).
3.2 Physiography and Geology
The Buriganga is being polluted day by day. For measuring the state of water quality of the river some objectives has been taken. To meet up that objectives extensive measurement is must. Physiographic and geology are very important to the present research. For finding out the result vast measurement has been conducted on physiographic and geology of study area. There has been a short description on these matters as follows:
3.2.1 Location
The Buriganga is located within 23°35¢ north latitude to 23°48¢ north latitude and 90°18¢ east longitude to 90°25¢ east longitude (Fig.3.3). Dhaka Metropolitan city is on the bank of northern side of the Buriganga River.
Figure: 3.1 Dhaka City and the Buriganga River. Source: After Nahar, 2000.
Figure: 3.2 Study Areas (Mirpur Bridge to Pagla). Source: After Nahar, 2000.
Figure: 3.3 Location of Buriganga River Source: After Nahar, 2000.
3.2.2 Physiographic Divisions
The Buriganga River is flowing through its flood plain containing both old and new alluvium. From Kalmar char to choto char it passes through the southern most part of the Madhupur tract which extends up to the northern extremity of the Buriganga basin. The southern bank and the flood plain is composed of newer alluvium of the Ganges and the Jamuna, carried to the Buriganga floodplain through the Dhaleswari.
Topographically the Madhupur tract is more elevated than the adjoining floodplain although floods might at times inundate the fringe of the terrace. Probably their higher relief is due not only to the more resistant nature of the materials to weathering and denudation but also due to the gradient uplift which the region has undergone. It has an elevation of about 20 feet on the east rising to about 100 feet on the west. On the south it dips gradually beneath the recent floodplain of the Buriganga and the Dhaleswari but on the east it forms an escarpment with a low angle (Khondaker, 1977).
The Buriganga basin may be classified into the following physiographic units (Fig. 3.4).
Closely dissected terrace
Mixed terrace outliers and floodplain
Active flood plain and
Old meander floodplain.
Closely dissected terrace: closely dissected terrace is composed of mixed red. Non-friable clays and loam to grey loams, mainly shallow and imperfectly drained with light grey silt clay loams in ralleys. They comprise level or rounded small chalas up to about quarter mile broad, usually rising abruptly 10 to 20 feet above broad valleys. The terrace has undergone human interferences as the city of Dhaka stands on it. Closely dissected terrace in the Buriganga basin in about 8 square miles (Khondaker, 1977).
Mixed terrace outliers and floodplain: Mixed terrace outliers and floodplain are the continuation of materials of the Madhupur terrace and recent floodplains. Closely dissected terrace stands on the west of the mixed terrace outliers and floodplain. Mixed terrace is composed of mixed red, non-friable clays, and loam to grey loams, and deep friable mettled soils, mainly yellow brown and grey, imperfectly to poorly drain. The comparatively low lying baids of the terrace have been filled up with the upland soils by erosion. The pagla, Fatulla and Syampur Khals are the principle seasonal streams which drain the terrace in the rainy season. The total area of the terrace is about 12 square miles.
Active floodplain: The active floodplain is the most widespread and elongated hypsographic unit of the Buriganga basin. The floodplain lies along the southern bank of the Buriganga. This area is annually inundated by flood water and the sand deposit on it is about 4 inches every year. In the upstream the sandy and silt clay loam of the Jamuna system is found while in the south and south-east the Ganges silt clay loam predominates. The total area of this unit is about 33 square miles. The topography of the floodplain is characterized by back swamps, channel bars, natural levees etc and other floodplain features (Khondakar, 1977).
Old meander flood plain: Old meander floodplain has been formed by the Buriganga, the Turag and their tributaries with in the study area. These tributary channels, when in flood, eventually breakout into the adjoining low lying lands to form new channels, subsequently laying down new deposits over the former basin deposits; and all times, following the mean during course of the tributaries. Near and around the confluence of the Buriganga and the Turag Kalmarchar, pitachaka and the Ghata char form part of the old meander floodplains. The total area of this unit is about 24 square miles (Khondaker, 1977).
3.2.3 Geology
The area in and around Dhaka, is physiographic ally located in the southern part of the Madhupur tract, which is one of the May or Pleistocene units of Bangladesh. Tectonically the area situated into the folded flank of the Bengal fore deep (Baktine). The geological formations delineated in the area are Pleistocene Madhupur clay and recent alluvium (Fig. 3.5) (Khondaker, 1977).
Figure: 3.4 Buriganga Basin Source: After Nahar, 2000
3.2.4 Soil
The soil of Buriganga River varies place to place. Closely dissected terrace is composed of mixed red, non friable clays and loam to grey loam, mainly shallow and imperfectly drained with light grey silt clay loam in valleys. Mixed terrace is composed of mixed red, non-friable clays and loam to grey loams, and deep friable mottled soils, mainly yellow brown and grey. In the upstream the sandy and silt clay loam of the Jamuna system is found while in the south and south-east the Ganges silt clay loam predominates. (Khondaker, 1977).
3.2.5 Buriganga River System
The river system of Buriganga River is spreaded in Dhaka city and in neighboring area of Dhaka City. Hydro logically, the river is not separated. Many rivers are interlinked with this river such as Balu River, Dhaleswari River, Kaliganga River, Sitalakhya River, Tongi khal and Turag River (Fig. 2.6). These rivers are also tributaries and brances of the Ganga, the Jumana and the Brahmaputra. Moreover, Dhanmondi Lake and Gulsan Lake also linked with the Burigangla River through Tejgaon, Mohakhali and Beghunbari khal. Most of the pollutants of savar, Dhaka Metropoliton area and Keranigonj area falling into the Buriganga river system. For this reason severe complexity is found in the hydrologic characteristics of Buriganga River. Major tributaries of the Buriganga River are dhulai khal, Shampur khal, Pagla khal and major branches are Jalokhali khal and painer khal (Nahar, 2000
3.2.6 Water Flow
The drainage area of the Buriganga from kolmar char to char Kamrongi is highly disrupted. The low lying areas to the north of Kalmar char upto Ghata char remaine under water from 6 to 8 months every year. (Khondakar, 1977). Then the river Buriganga is flowing through a strait channel from char Kamrangi to Fatulla and it then takes a sharp turn to the south to join the Dhaleswari (Khondakar, 1977). In this river, less influence of ebbs and tides is found in rainy season (June-October) and influence of ebbs and tides is high in winter season (November- May). If back water effect is exist in rainy season the river can also be changed into tidal river. But the tidal range of this river is not much high. In 1993 the tidal range was highest 0.75 metre, it varies year to year but its range is normally very low (Nahar, 2000).
Figure: 3.5 Geological map of Buriganga Basin. Source: After Nahar, 2000.
Figure: 3.6 Buriganga River System. Source: After Nahar, 2000.
3.2.7 Climate
Laying with the humid tropical zone the Buriganga basin is governed by the tropical monsoon type of climate. The general characteristics of this type of climate are heavy rainfall, high temperature, often excessive humidity and fairly marked seasonal variation.
The basin area receives concentrated rainfall from April to October which averages 90 inches annually, the Madhupur tract in the north receiving comparatively more. The area is also affected by tropical cyclones, northwesters, associated with tornado which causes heavy rainfall