INTRODUCTION:

Water is a vital resources used for various activities such as drinking, irrigation, fish production, industrial cooling, power generation and many others. Presence of Dissolved Oxygen, Chemical Oxygen demand, conductivity and P^H are significant parameters to study water quality. Higher conductivity is harmful for irrigation purpose. Level of specific conductivity depends on the inputs of large amount of salts¹.

The P^H indicates hydrogen ion concentration. Most of the plant and animal species can survive a narrow range of P^H from slightly acid or slightly alkaline conditions, drastic P^H changes adversely affect them.

Nitrates are dangerous to human health especially in case of infants below 6 months of age ². Nitrate contamination of ground water can be a serious problem in rural areas, where ground water is the major source of drinking water.

Ground water is the most important source of water supply for drinking, irrigation and industrial purpose. So it is necessary to analysed the water samples and take preventive measures to control the pollution of water.

Experimental Details:

Environmental pollution is one of the most horrible ecological crises to which we are subjected today. We know that three basic amenities for living organisms are air, land / soil and water³.

Rapid industrialization has left with us polluted rivers contaminated soil, depleted wild life and exhausted natural resources.

When different spheres of the environment are affected by pollution, then can be categorized as: -

i) Air Pollution

ii) Water Pollution

iii) Soil / Land Pollution

Water is the most vital resource for all kinds of life on this planet is also the resource adversely affected both qualitatively and quantitatively by all kinds of human activities on land in air or in water. Water forms about 75% of the matter of earth crust ⁴.

The chief sources of water supply for industrial purposes are Ground water, Surface water, Sea water and Rain water.

Many experiments have now being carried out for converting sea or ocean water and sewage effluents into potable or drinking water.

Pollution of water bodies is increasing steadily due to rapid pollution growth, industrial proliferations, urbanizations, increasing living standards and wide spheres of human activities ⁵.

Water pollution is the main cause of the high incidence of Typhoid, Hepatitis and other Intestinal infections⁶.

The scope of the present work is with the intension to study the equality of the ground water at various place of the Aurangabad City under different conditions of season and these by its viability for the healthy consumption.

Table No. 1

Sr. No.

Parameter

Site

Seasons

I April

II Sept.

III Dec.

Temperature

39⁰C

38⁰C

28⁰C

26⁰C

20⁰C

18⁰C

Colour

Pale green

Colourless

Pale green

Colourless

Pale green

Colourless

Odour

Indistinct

Odourless

Indistinct

Odourless

Indistinct

Odourless

Viscosity (Centipoise)

1.041

1.103

1.126

1.082

1.098

Demand Oxygen (mg/l)

5.2

3.3

3.9

4.4

3.7

BOD

5.2

1.2162

4.8648

1.2162

2.4324

1.2170

COD (mg/l)

154.65

138.65

53.33

154.65

53.33

Conductivity (mmhos)

1.226

1.087

0.556

1.087

0.440

0.409

p^H

7.01

7.26

7.32

7.42

7.83

7.15

Chloride (mg/l)

118.76

81.535

58.49

70.90

120.53

134.71

Alkalinity HCO₃ (mg/l)

640

690

470

410

600

510

Calcium (mg/l)

128.25

140.28

120.24

140.28

100

220

Magnesium (mg/l)

0.5612

0.976

0.732

0.488

Zinc (mg/l)

1.50

1.80

2.48

3.30

Water samples from various sites of the Aurangabad region were collected in a precleaned bottles.

Ø The temperature of the sample was recorded.

Ø DO was determined by Winkler’s method.

Ø p^H of the samples were determined.

Ø Density by usual method.

Ø Viscosity by viscometer.

Ø Chloride by Mohr’s method.

The other parameters such as hardness, Ca, Mg and Zn were determined titri-metrically using standard methods.

The experimental method were followed as per the standard methods and procedures as given below ⁷.

1. Colour:

True colour is the colour caused by dissolved substances such as salts and colloidal impurities. Colour is determined by visual comparison of the sample with known concentration of coloured solution.

2. Odour:

Can be determined by diluting the sample with odour free water until the last perceptible odour is achieved.

3. DO Principle:

DO rapidly oxidizes the divalent manganous to its higher valency which forms a brown hydrated oxide ppt. after addition of NaoH and KI. In the presence of iodide ions in an acidic solution the oxidized manganese reverts to the divalent state and liberates iodine from KI equivalent to the original DO content. The liberated iodine is then titrated against standard sodium thiosulphated solution with starch as an indicator MnSO₄ reacts with alkali to form white ppt. Mn(OH)₂ thus indicating absence of oxygen in the sample.

Procedure: Collect the sample in a 300ml BOD bottle

Ø Add 2 – 3ml of Winklers A solution and 2 – 3ml of Winklers B solution well below the surface through the walls.

Ø Stopper immediately to remove air bubbler and mix carefully by inverting bottle up and down.

Ø Allow the brown ppt. to settle down leaving clear supernatant.

Ø Add conc. H₂SO₄ drop by drop till ppt. is digested.

Ø Restopper the bottle and min by inverting several times for complete dissolution.

Ø A yellow coloured solution appears.

Ø Take 50ml sample in a conical flask.

Ø Add few drops of starch indivator and titrate against (0.02N) Na₂S₂O₃ solution.

Ø End point blue to colourless.

4. BOD:

BOD is an empirical test which measures the oxygen required by the micro organisms for the biochemical degradation of organic matter to CO₂ and H₂O.

Procedure:

Ø Take 5 liter of diluted water and aerate by bubbling compressed air to attain DO saturation.

Ø Add 1ml each of PO₄ buffer, magnesium sulphate CaCl₂ and FeCl₃ solution for every liter of diluted water.

Ø In case of the waste waters which don’t have sufficient bacterial population, ass seed to the dilution water. For 2ml settled sewage 1000ml of diluted water is sufficient.

Ø Maintain the p^H 7 if samples are acidic or alkaline.

Ø For destroying residual chlorine if present add 2 or 3ml of sodium sulphate solution.

Ø Take the sample dilutions as follows:

Strong wastes - 0.1% or 1%

Raw sewage - 1% or 5%

Treated effluents - 5% or 25%

River water - 25% or 100%

Ø Prepare dilute sample with diluted water and min the contents well.

Ø Take diluted sample into 2 BOD bottles.

Ø Fill another two BOD bottles with diluted D/W alone.

Ø Find immediately DO of a diluted waste water and diluted D/W alone.

Ø Incubate at 20⁰C for 5 days the other two BOD bottles. Tightly stopper to prevent any entry of air into the bottles.

Ø Determine DO content in the incubated bottles at the end of 5 days by using DO estimation method.

5. Chemical Oxygen Demand (COD):

Procedure:

In the reflux flask add 20ml of sample, 10ml of K₂Cr₂O₇ solution.

Ø Add a pinch of AgSO₄ and also mercuric sulphate along with 30ml of H₂SO₄.

Ø Now attach the condenser to the mouth of flask – for refluxing the contents heat and flask on a water bath or heating mantle for atleast 2 hrs. – after 2 hrs remove the flask and cool it add approximately 150ml of D/W to dil. Its contents.

Ø Now add 2-3 drops of ferroin indicator and titrate against ferrous ammonium sulphate solution till the colour changes from yellow to wine red.

Ø Run a blank using the D/W following the same procedure.

6. p^H:

Procedure: In each case follow the manufacturer’s instructions:

Ø Remove electrodes from storage solution rinse blot with dry soft tissue paper, place in initial buffer solutions and set the potential point.

Ø Select the second buffer solution and adjust the p^H and bring the sample and buffer to the same temperature.

Ø A fix temperature such as 25⁰C or the temperature of fresh sample should be fixed before measurement of any p^H.

Ø In the sample solution dip the electrodes and swirl the solution and wait for a minute.

Ø Note down the readings.

7. Chlorides (Cl):

Ø Take 100ml of the sample in a conical flask.

Ø Adjust its p^H to be between 7 to 10 either with H₂SO₄ or NaOH.

Ø Add few drops of H₂CrO₄ indicator it turns yellow.

Ø Titrate with standard silver nitrate solution till colour changes from yellow to brick red.

Ø Record the volume of silver nitrate added.

Ø Establish a blank by titrating D/W in the same manner for better accuracy.

Ø Record the volume of silver nitrate added for D/W.

8. Calcium Hardness:

Ø Take 50ml sample in a conical flask.

Ø Add 2ml NaoH to produce a p^H of 12 to 13.

Ø Add 0.1 to 0.2g or a pinch of murexide indicator.

Ø Titrate the contents with EDTA solution until the pink colour changes to dark purple.

Ø Note the volume of EDTA used.

9. Magnesium Hardness:

Ø Take 100ml of the given sample in a conical flask.

Ø To remove residual chlorine if present add 1 drop of 0.1N sodium thiosulphate solution.

Ø Add 2 drops of the phenolphthalein indicator.

Ø If the solution remains colourless, then PA is zero indicating absence of carbonates.

Ø If the sample turns pink run down 0.02N H₂SO₄ till the solution turns to colourless.

Ø Note down the volume of H₂SO₄ added (V₁).

Ø Add 2 drops of methyl orange indicator the sample turns yellow.

Ø Titrate till the colour of the sample turns pink.

Ø Note down the total volume of H₂SO₄ added (V₂).

10. Zinc (Zn):

Ø Take 10ml of unknown sample in a conical flask.

Ø Add 2ml of buffer solution and few drops of EBT as an indicator.

Ø The colour of the solution turns to blue.

Ø Titrate this mixture against EDTA solution.

Ø The end point of the solution changes from blue to violet.

11. Viscosity:

Ø Clean the viscometer with chronic acid, rinse with acetone and dry with drier.

Ø Attach a piece of rubber tubing to the capillary end of viscometer and fix the viscometer to the stand exactly vertical.

Ø Take 20ml of D/W and 20ml of given liquid and keep them in a thermostat to attain the same temperature.

Ø Introduce D/W into the viscometer by means of pipette.

Ø Such the water through rubber tubing till it comes above the upper mark (Mark – A).

Ø Allow it to flow through capillary.

Ø Start the stop watch as soon as level of water coincides with mark A.

Ø Note down the time required for water to flow down level A to B.

Ø Take three readings and note mean of flow time of water as t₁.

Ø Remove the water from viscometer and clean it.

Ø Introduce liquid in the viscometer and find out flow time for given liquid as t₂.

RESULTS AND CALCULATIONS:

The results of physico chemical analysis are present in the table 1. The standard values according to ISI, WHO and USPHS ⁸ is also given in table 2.

Table No. 2: Drinking water standards according to ISI, WHO, USPHS. The following values in table shows the USPHS standards for the water

Sr. No.	Parameter	Standard Values
1	COD	10 mg/l
2	p^H	6.5 – 8.5
3	Chloride	200 – 600 mg/l
4	Alkalinity	200 – 600 mg/l
5	Calcium	75 mg/l
6	Magnesium	30 – 150 mg/l
7	Zinc	50 mg/l

Ø Temperature: The samples had temperature ranging from 39⁰C to 18⁰C. It is evident that the surface water temperature was higher in the month of April and gradually decreases during the month of December.

Ø Colour: Water samples are colourless for site B where as site A show pale green colour due to the presence of biological substances.

Ø Viscosity: The relative viscosity shows the variations in the range between 1.041 to 1.126 centipose. Variation in the sample indicates presence of pollutants in the water sample in the form of dissolved biological substances or chemical substances.

Ø Dissolved Oxygen: The recommended DO limit for all the domestic purposes in 4.5mg/l. DO values greater than 4mg/l in the water body is satisfactory. Higher values of DO indicate the rate of O₂ utilization. In the present study the DO is in the range from 3.3 to 5.2mg/l.

Ø BOD: is a way of expressing the amount of organic compounds in sewage as measured by the volume of oxygen required by bacteria to metabolize it under aerobic condition. The value obtained in the present study ranges from 5.2mg/l to 1.21mg/l i.e. it is considered moderately clean.

Ø COD: Values were higher ranging from 154.65mg/l to 53.33mg/l.

Ø Conductivity: Conductance of samples varied from 0.007 to 1.659 mmhos.

Ø p^H: indicates the acidic or the basic nature of water. The p^H of the samples varied from 7.01 to 7.83. The standard limit is 6.5 to 8.5.

Ø Chloride: is found to be in the range of 42.54 to 177.25mg/l. This is within the desirable limit.

Ø Calcium and Magnesium: The Calcium and Magnesium in the water samples is within the desired limits.

Ø Zinc: levels ranges from 0.91mg/l to 3.30mg/l maximum value was recorded in the month of December.

REFERENCES:

1. Deshmukh, J.U. and Ambore N.E., J. Aqua. Bio., Vol. (2) 2006, 93 – 96.

2. Sandeep Mitharwal, R.D. Yadhav and R.C. Angasaria Int. J. Chem. Sci. 7 (3), 2009, 1725 – 1732.

3. International J. of Environmental Protection 26(2); 116 – 124 (2006)

4. International J. of Environmental Protection 26(6); 521 – 524 (2006)

5. International J. of Environmental Protection 26(10); 872 – 876 (2006)

6. Garg, U.K. 1999 An appraisal of ground water quality in some villages of district Jind. Indian J. Env. Prot. 19: 267 – 272.

7. Rajagopalan, 2005 Environmental studies from crises to curve. Oxford Pub. 190 – 191.

8. USPHA, 1962, Drinking water standards United States Public Health Association.

Received on 02.05.2012 Modified on 21.05.2012

Asian J. Research Chem. 5(7): July, 2012; Page 871-874