Analysis of physicochemical parameters of the Hebbal, Shivpura, Elemallappa Shetty Lakes in Bengaluru City, India

Water is the most important compound in shaping the land and regulating the climate. It is one of the crucial compound that is believed to infl uence life. The water quality is usually described according to the physical, chemical and biological characteristics. The indiscriminate release of chemical fertilizers, pesticides, industrial effl uents are causing heavy and varied pollution in the aquatic environment leading to the deterioration of water quality which in turn depletes the aquatic biota.


Introduction
Water is the most important compound in shaping the land and regulating the climate. It is one of the crucial compound that is believed to infl uence life. The water quality is usually described according to the physical, chemical and biological characteristics. The indiscriminate release of chemical fertilizers, pesticides, industrial effl uents are causing heavy and varied pollution in the aquatic environment leading to the deterioration of water quality which in turn depletes the aquatic biota.
The use of the contaminated water by human population results in water borne diseases. Hence it is important to check the water quality at a regularly. The present paper investigates some important physicochemical parameters of water samples collected and do a statistical inference on the same. Three lakes in Bengaluru city like Hebbal lake in Northern Bengaluru, Shivpura lake and Elemallappa Shetty Lake in Southern Bengaluru were selected to study the physicochemical parameters, as these lake waters were polluted by industrial effl uents, agricultural run off, domestic discharges etc. physicochemical parameters like color, odour, pH, temperature, dissolved oxygen, biological oxygen demand, turbidity, electrical conductivity, chlorine content, metals content like Magnesium, Chromium, Iron, Tin, Mercury, Calcium were studied and statistically analyzed for a period of 12 months from January, 2019 to December, 2019. A general applied mathematics study and analysis on the biophysical and chemical parameters of the lake's surface water quality are applied to seek out the interrelatedness among them and conjointly to understand the water quality trends within the lake. The equation has been derived for the surface water quality parameters similar to the correlation coeffi cients whose value is over 0.8. These equations will be used for the fast observation of the surface water quality of the lake. Similarly, a scientifi c correlation and regression study on the surface water qualities within the study space showed linear relationship among the chosen parameters. This provides an apparent and fast methodology of observation in qualities of the lakes studied. Water quality of the lakes has been determined.
Water quality of the lakes is studied to summarize the collected information into easy terms (e.g., 'Good' or 'Bad', 'Clean' or 'Contaminated') for news to authorities, management and therefore the public in an exceedingly consistent manner. It is important to note that no work has been reported on Hebbal, Shivpura and Elemallappa Shetty Lakes earlier.

Study area
Hebbal Lake is found within the north of Bangalore at the mouth of National main road seven, on the junction of Bellary Road and also the Outer route (ORR). it absolutely was one in all the 3 lakes created in 1537 by Kempe Gowda. The unfold of the lake in a very study in year 2000 was found to be seventyfi ve angular distance with plans for extending it to create up 143 angular distance. Shivapura is found 5 kilometers north of Maddur city on the bank of Shimsha watercourse. Shivapura is an element of Mandya taluk in Mandya district, Karnataka. the situation coordinates square measure 13°1'24"N 77°30'23"E. settled nearer to 1 of Asia's largest industrial parks-the Peenya Industrial Estate-the Shivapura-Nelagadarenahalli lake goes the Bellandur method. Elemallappa Shetty Lake is within the North-Eastern a part of Bengaluru town close to Whitefi eld. This lake is about 260 acres. This is one in all the biggest lakes in Bengaluru town. This lake has the recent Madras Road passing through it -a road that has very important property from the central Bengaluru through Indiranagar, KR Puram, Hoskote, Chennai. pH pH is that the measure of acidity of any water solution [1][2][3]. The pH unremarkably ranges from 0 to 14 [1][2][3][4]. the size isn't linear rather it's logarithmic. as an example , a solution with a pH of 6 is 10 times additional acidic than a solution with a pH of seven [1,3,4,5]. Pure water is claimed to be neutral, with a pH of 7 . Water with a pH below 7.0 is taken under consideration acidic whereas water with pH bigger than 7.0 is taken under consideration basic or alkalic [6]. The measure of Ph was done on the location of water collection. Ph meter was used for detection of Ph of the collected water samples [7-18].

Temperature
The temperature of all collected water samples from 3 locations were at intervals of 23ºC to 31ºC. The minimum temperature was found to be 23.2ºC in Shivpura Lake within the month of January. Temperature range is found to be low during the post monsoon periods of July and August [19][20][21]. Pre monsoon months and summer months have an increase in temperature to 30.7ºC. the general seasonal variation in temperature is being observed all-round the year [21,22]. The temperature fl uctuations don't provide a drastic shock to the sustaining aquatic life [23]. Surface water temperature could also be infl uenced by factors like geographical position, seasonality, diurnal amount, circulation of air, amount of inclemency, depth of water and its rate [11][12][13][14][15][16].

Electrical conductivity
Conductivity is the measure of amount of electric charge which can pass through the water samples [18]. This ability depends on the presence of ions, their total concentration, mobility, valence and relative concentrations, and on the temperature of the liquid [23]. Solutions of most inorganic acids, bases, and salts square measure comparatively smart conductors. The EC of all collected water samples from 3 locations were at intervals of 0.6 to 2.3 μS/cm with a mean of 1.43 (SD±0.85). The maximum and minimum of EC was found to be 0.61 μS/cm and 2.7 μS/cm respectively during the monsoon months. From the study, the measured EC of all water samples collected from Hebbal, Shivpura and Elemallappa Shetty Lake was lower than acceptable range. Within the monsoon season, the fl ow of the watercourse will increase which can cause the dilution of the salinity of the water, whereas in season, the fl ow of the watercourse decreases which ends up in increase of EC [21].

Dissolved oxygen (DO)
DO is defi ned as the amount of oxygen dissolved in the water samples. It's essential for respiration of fi sh and other aquatic organisms [3]. DO enters water by diffusion from the atmosphere, as a by product of chemical process by protists or through photosynthesis performed by plants [24][25][26][27][28][29][30]. The concentration of DO in waters depends on the organisms surviving in it, because all metabolic processes taking place utilizes the dissolved oxygen available [9]. Excessive protist or other microorganism in the aquatic environment depletes the amount of dissolved oxygen and it affects the metabolic processes performed by other macro organisms [10][11][12][13][14][15][16]. Other processes like decomposition of dead performed by different scavengers in the aquatic environment utilizes the dissolved oxygen [11,12]. Fish want a minimum of 3-5 mg/L of DO to survive [21,23,[30][31][32][33][34]. DO is observed to vary within the range of 13.13 mg/L to 28.28 mg/L with the mean of 19.98 mg/L. Winkler's method was carried out on the site of sample collection to measure the DO [25]. About 1 ml of manganous sulphate, 1 ml of potassium/sodium azide are added to 120 ml of sample water samples from the three distinct sites [25]. Brown precipitation was observed which indicated the presence of dissolved oxygen in the collected water samples [9,25,29,35]. About 1 ml of concentrated H 2 SO 4 was added and titrated against sodium thiosulphate and starch solution was used as an indicator [25,29]. The colour change from blue to pale yellow marked the level of DO content [25,11].

Turbidity
Turbidity is defi ned as the cloudiness or haziness of a fl uid. It can be caused by large numbers of individual particles that are generally invisible to the naked eye [36][37][38]. Water samples were collected from three distinct lakes and a nephelometer or turbidimeter was used to measure turbidity of each water sample [39]. Nephelometer or turbidimeter is an instrument which measures the intensity of light scattered at 90 degrees as a beam of light passes through a water sample [40]. It is observed that turbidity varied within the range of 0.35 NTU to 10.9 NTU. The mean is found to be 4.822 NTU (SD±4.522).

Biological oxygen demand (BOD)
Biological oxygen demand (BOD) is that the quantity of biological organisms to break down the organic materials at a certain temperature over a specifi ed time interval [41][42][43]. The water samples were collected from each study site in 120 ml BOD bottles and kept in kept in incubation for 5 days [40,44].
After 5 days the DO was measured using Winkler's method. The difference between the readings of DO (Day 1) and DO (Day 5) gives the BOD reading [40,[45][46][47]. The difference between the two DO levels represents the amount of oxygen required for the decomposition of any organic material in the samples [48][49][50].
The mean of BOD was observed to be 8.08 (SD±10.456). The decrease in DO level in the water sample of Elemallappa Shetty Lake was more compared to other water samples. This may be because the organic material content in the water sample collected from Elemallappa Shetty Lake is more comparatively.

Platinum cobalt unit test
Water samples from three distinct sites were collected and kept at room temperature [8]. The collected water samples were analyzed within 7 days of collection. Samples were fi ltered using fi lters of defi ned pore size. The 0.45 ~m fi lters were used for routine fi ltration. Standard color solutions were prepared by dilution of standard platinum chloride (I ms/ml,) and cobalt chloride (CoCl.6H 2 0) solution. The molar ratio of Pt :Co its the standard color solution is 2:1 ~ the concentration of Pt in mg/i is equal to the "color" in PTU [8]. Color was determined using turbidimeter. The detection of water color specify the extent to which collected water samples are polluted [8]. Shivpura lake water samples had the highest NTU compared to other water samples.

Statistical analysis
The correlation analysis on surface water quality parameters reveals that all parameters are more or less correlated with each other. The correlation coeffi cient (r) of > 0.8 was taken in to account to fi nd the regression equations. The SPSS and Windows Excel were used as the statistical analysis tool. The term correlation (or co-variation) indicates the relationship between two variables such that the changes in the values of one variable cause the value of the other variable to change.
We can establish inter-relationship between variables by statistical methods with a few sets of observations. It gives a rough but fairly useful indication of the water quality and also facilitates a rapid monitoring of the status of water pollution.
Statistical investigation offers more attractive options in environmental science, though the results may deviate more from real situations. The correlation provides an excellent tool for the prediction of parametric values within a reasonable degree of accuracy [58]. The quality of water is described by its physical, chemical and microbial characteristics. But, if some correlations are possible among these parameters, then the more signifi cant ones would be useful to indicate fairly the quality of water [10,59,60].   less, Hebbal Lake water samples are safe for use since the Chromium content was less, but for Shivpura and Elemallappa

Discussion
Shetty Lake water, pre use treatment is required before use.
All the water samples contain Calcium within permissible limit that is 75 mg/l, thus safe for use. Overall, Hebbal and Shivpura Lake water samples are of good quality but Elemallappa Shetty Lake is of poor quality. Elemallappa Shetty Lake water contains most amount of pollutants and need pre use water treatment.
Based on this study it is been found that water resources potential analysis in terms of quantifi cation of surface water is important to evolve water resources development plans for the lakes in metropolitan cities like Bengaluru. Initiatives are taken to popularize the programs among the general public, particularly farmers at numerous levels, that ought to be created effective thus on attain self-suffi ciency within the property water resources development. Prioritization ought to run within the over-extracted areas in the city thus on conservation of the water and for designing acceptable structures to be placed into action.

Conclusion
The results of seasonal variation and physico-chemical study of the lake water samples, helps us to conclude regarding the quality of the water samples studied. Jobi Xavier, for their continued support and encouragement.