Abstract

Of the globe’s total water resources, less than three percent is fresh water. Fresh water for human consumption is a fragile and finite source and is a critical component of the global environment. Water is called the universal solvent” because it dissolves more substances than any other liquid. Water quality of a lake is the reflection of the physio-chemical properties of water, the clearer the water, the more it will reflect the light and the higher the intensity the scattered light, the higher will be the turbidity. Water resources are equally important for all forms of life& without good water quality life is impossible. Fresh water is a critical, finite, vulnerable, renewable natural resource on the earth and plays as important role in our living environment. More than 70% of the Earth's surface is covered by water. The result of our study showed that there was no significant difference in the surface water temperatures of the four sampling sites. Ph of sampling site 1 was lower than the S1, S2 and S3. Dissolved oxygen (DO) was same at all sites while as free carbon dioxide showed slight difference at site 1, which was higher than S1, S2 and S3.The analysis of physicochemical variables of water samples collected from the four selected sites of Upper Lake revealed that Site I showed conspicuous significant differences in the various parameters analyzed.

1. Introduction

Water exists in three states i.e., solid, liquid and vapors being universal solvent. Water is required for all life processes like irrigation, drinking water, industries, swimming, and fishing. The different components of water are analyzed on the regular basis. The water pollution is a severe problem now days because everything is dependent on water, no one can survive without water and it affects the lives of many populations. As with time population is increasing rapidly it is also giving rise to variety of impurities being added each day to natural water of rivers like- increased industries and use of fertilizers means more effluents and chemicals. Water is contaminated by different agents such as microbial and chemical contaminants. Microbial contaminants are harmful than that of the chemical contaminants and affect human health more than that of the chemical contaminants ¹. Due to the contaminated water two millions of children die on regular basis every year, approximately 1.8 million children die from diarrhea every year ². Water is the essential component on earth gifted by nature to mankind. In earth ecosystem, biogeochemical cycle and in biosphere water performs unique and indispensable activities, thus living organisms require large amount of water for their survival. Among the natural resources water is the most important component, it is also known as Blue Gold because without water human civilization and evolution of life on earth is not possible. Water is used for many purposes like transportation, domestic, industrial, hydroelectric power, and commercial uses. About 70.9 percent of the landmass is covered by water. In aquifers it also exists as groundwater ³. Human health is directly affected by the quality of water ⁴ therefore continuous monitoring of water from time to time for its quality is very important. Keeping in view of human health Physico-chemical parameters along with trace elements and biological properties of water must remain free from harmful pollutants. If impurities are present in water, we faced a lot of problems and we may suffer from water borne diseases like typhoid, cholera, jaundice etc. A complete assessment of water quality is based on the monitoring of vital components like hydrological, physio-chemical and biological must be done continuously to have the updated information’s. Human body consists of 75 percent of water. Water regulates various activities in the body like fluids, tissues, cells, lymph, flood and granular secretion thus water acts as a life line for us. Out of 71 parts of water on earth, we use only one percent of water on earth, about 97 percent water is sea water, and 2 percent is in frozen glaciers and polar ice caps. The disease caused by the lack of water is known as dehydration; dehydration is more fatal in comparison to starvation (lack of food is known as starvation). If the drinking water is contaminated, then the scenario gets worse as it is not only the cause of illness but results in death in number of cases ⁵. Water pollution adversely alters the quality of water, disturbs and destroys the balance of ecosystems and causes hazards to public health.

Water becomes polluted by the presence or addition of inorganic or organic substances or biological agents. Soil erosion, leaching of minerals from rocks, decaying of organic matter is natural sources of water pollution ⁶. According to WHO, Water pollution is defined as the inclusion of any foreign material either from natural or other sources present in a water body, thereby changing the natural qualities of water and making it unsafe for use. The impact of pollutants depends upon its properties and amount. The biological effects of chemical pollutants are various. Heavy metals in water such as lead and mercury (Pb, Hg, Cr) cause illness such as cancer, nervous system disorders and birth defects ⁷ lead is cancer causing metal. Some compounds are so corrosive that they may even affect waste treatment plants. Organic sulphur compounds interfere with nitrification. Inorganic nitrates and phosphates stimulate excessive plant growth in lakes and reservoirs, this is called eutrophication. The organochlorines from pesticides are highly persistent and pass-through food chains. Impairment of taste caused by industrial effluents containing iron, free chlorine, phenol, manganese, detergents, oil, hydrocarbons and decomposition products ⁸.

2. Materials & Methods

The research work is carried out in the Upper Lake of Bhopal commonly known as “Bada Talab” or “Big Pond” which serves as a major source of drinking water for the residents of the city and serving around 40% to the resistant of the city. Bhoj wetland of Bhopal city is a combination of two important water bodies namely Bada and Chota Talab. In Hindi the word “Talab” means lake and Bada Talab is one of the majortourist attractionsin Bhopal city. It is one of the largestartificial lakes and is dedicated to the king Pamara Raja Bhoj. The water sample collections were done at every sampling station and temperature of water was recorded immediately at the sitesand then the water samples carried to the laboratory for further water analysis. Four sampling stations were chosen for the collection of water samples. The description of the study area is given in Table 1 and Figure 1.

For physio-chemical analysis of water, the “UpperLake” was divided into four zones. In each zone, one sampling station site was selected for the collection of water sample. Total four sampling sites designed as S1, S2, S3 and S4 were established so as to cover the maximum area of the lake. Theses all sampling stations are free from tourist disturbance. At every sampling station, in the first week of every month, water samples were taken between 6-8 A.M. Water temperature of the collected water samples were taken immediately at every sampling stations. The sampling stations are mentioned below in Table 2 and Figure 2. (S1-S4).

a) Temperature of water

The seasonal as well as spatial temperature variations were recorded on the 1^stday of every month at each sampling site with the help of a centigrade mercury thermometer graduated from 0 to 110°C. The temperature of S1, S2, S3 and S4 were taken from equal depths in the morning hours between 8-9 A.M.

b) pH

Ph is the measure of the intensity of acidity or alkalinity and measures the concentration of hydrogen ions in water.

Ph meter is a scientific instrument that measures the hydrogen ion activity in water-based solutions, indicating its acidity or alkalinity expressed as ph. Here pH of water was determined by Electrometric method i.e., digital pH meter. The pH was measured just after the collection of water samples from sites because pH might change with time due to the possibility of various types of interactions reactions within the water sample such as hydrolysis reactions, absorption loss of certain gases, oxidation or reduction reactions, etc. The ionic power of hydrogen ions is measured by dipping electrode in water ⁹.

c) Hardness

Total hardness was determined by using EDTA titration method The EDTA (Ethylene Diamine Tetra Acetic Acid) and its sodium salts form the soluble compound when added to a solution of certain metal cations. This action is indicated by using small quantity of dye such as Eriochrome black T indicator (APHA, 2012). The hardness is calculated by following formula.

The hardness is expressed in terms of mg equivalent of CaCO3/ L.

d) Free Carbon Dioxide (CO₂)

Free carbon dioxide was determined by the simple titrimetric method. 50 ml of sample was taken in a conical flask and 2-3 drops of Phenolphthalein was added as indicator. If the sample does not become pink and remain colorless it indicates the presence of CO₂ in the water sample. Immediately the sample was titrated against sodium hydroxide (NaOH) solution (0.05 N) until a faint pink colour appeared at the end point. The amount of free CO₂ is the volume of NaOH consumed. Three readings of burette were noted and mean was taken which later on calculated by using the following equation as mg/l.

Where, N = Normality.

e) Dissolved Oxygen (DO)

Dissolved oxygen refers to the level of free, non-compound oxygen present in water or other liquids. It is important parameter in assessing water quality because of its influence on the organisms living in water bodies. Dissolved oxygen of water was determined by Winkle’s method. The water was collected in glass topper bottle and the dissolved oxygen was fixed by the addition of manganese solution (MnSO₄). 2 ml of concentrated sulphuric acid was added through the side of the bottle and was shaked well to dissolve the precipitate. 50 ml the above solution was taken in conical flask and titrated with 0.025N thiosulphate solution using starch as an indicator to a colorless end point (APHA, 2012). The dissolved oxygen is calculated by following formula.

Where,

X- Volume of sodium thiosulfate (ml)

Y- Volume of sample (ml)

N- Normality of sodium thiosulfate (0.25 N).

The dissolved oxygen is expressed in terms of mg/l.

f) Alkalinity.

Total alkalinity was estimated by using titration method with a strong acid like hydrochloric and using methyl orange and phenolphthalein solution as indicators.

The hydroxyl ions existed in sample as an effect of hydrolysis of solutes react with addition of standard acid. At this point the phenolphthalein alkalinity is calculated first and then total alkalinity is calculated (APHA, 2012). The total alkalinity is calculated by following formula.

Where

A= ml of titrant used

N= Normality of titrant

The total alkalinity is expressed as mg equivalent of CaCo₃\l.

3. Result and Discussion

Evaluation of the water quality in four selected sites of Upper Lake Bhopal was carried out during the pre-monsoon (April, May and Mid-June 2019) season showed slight differences in physio-chemical parameters at all sampling site. Statically there is no significant difference. The analysis of physicochemical variables of water samples collected from the four selected sites of Upper Lake revealed that Site I showed conspicuous significant differences in the various parameters analyzed.

4. Physical Parameters

Temperature is main physical factor of any habitat and a significant variation was observed in the Site I (Table 3). Mean water temperature in Site I was 37°C, that in Site II was 35°C. The fluctuation in temperature between Site I (Shani Mandir) and Site II (Boat club) was statistically non-significant. The average temperature in Site III (Bairagarh Visargan) was 33°C. The temperature in Site IV (Chirayoo Hospital site) is 34°C respectively.

The pH of water samples also exhibited variations with a significantly low value in Site I. The water sample in Site iv showed the highest pH value of 7.36 whereas it was 6.1 at Site I. In Site II the average pH was 6.88. The pH of water samples collected in Sites III was 7.07.

Hardness of water is intolerable from the view point of water use for laundry and domestic purposes since it consumes a large quantity of soap. Total hardness of the four sites varied from 41.3 to 43.4. However, the permissible limit of Hardness for drinking water is 300 mg/l (IS 10500). According to Hardness classification ¹¹, the no of water samples of the study area can be classified as given in Table 5.

Dissolved oxygen content in water reveals the physical and biological procedures prevailing in water and is influenced by aquatic vegetation. Low oxygen content in water is usually associated with organic pollution. DO of site I is 7.69, site II is 7.97, site III is 7.8 and site IV is 7.62.

In the present investigation Phenolphthalein Alkalinity was not found in all samples and Methyl Orange Alkalinity was extended from 96 mg/l to 102.4 mg/l, this proves the absence of Hydroxyl and Carbonate and proves the presence of Bicarbonate. However, the prescribed limit for Total Alkalinity is 130 mg/l.

Free carbon-dioxide concentration was variable. The highest concentration 6.5 mg/l at site I and least at site III i.e., 3.9. CO₂ is soluble in water. The photosynthetic process of planktons in aquatic surroundings is reflected as a critical factor for the variation of CO₂ and PH level. Free CO₂ of water from carbonic acid (H₂CO₃) which dissociates into H⁺ and HCO₃ ions. This brings change in PH of water. The decomposition of organic matter produces much CO₂ and respiratory activity of aquatic plant and animals which are the most important factors of CO₂ fluctuations.

5. Conclusion

The result of our study showed that there was no significant difference in the surface water temperatures of the four sampling sites. Ph of sampling site 1 was lower than the S1, S2 and S3. Dissolved oxygen (DO) was same at all sites while as free carbon dioxide showed slight difference at site 1, which was higher than S1, S2 and S3. The analysis of physicochemical variables of water samples collected from the four selected sites of Upper Lake revealed that Site I (Shani Mandir) showed conspicuous significant differences in the various parameters analyzed. The physio-chemical properties of Upper Lake Bhopal show slight differences which are statically non-significant.

References