Determination Of Water Classification Properties pH And Conductivity Of Different Delhi And NCR RegionB.MeghaDepartment Of Information TechnologyIndira Gandhi Delhi Technical University For womenKashmere Gate, Delhi, India

Abstract: In this paper I represent pH and conductivity of various samples water collected from different parts of delhi and near capital territory(north delhi, south delhi, east delhi, waest delhi, gurgaon, faridabad). The main objective of this study was to classify domestic water on the basis of ph and conductivity.The present study provides a glimpes of the ph and conductivity values of the domestic wate supplied and its effects. During the study the highest pH (8.10-8.12) was found in west delhi region and highest conductivity(5.10) was recorded in north delhi region.

Introduction

pH and conductivityTwo measurements often made on water matrices are pH and conductivity. These are usually categorized as physical tests, though they are strongly dependent on the chemical characteristics of an aqueous solution. The tests are easy to conduct and are usually performed shortly after obtaining a sample. Constant values from day to day give some indication that conditions are stable; and correspondingly changes in these parameters suggest that underlying conditions are also changing.

pHpH is a measure of the hydrogen ion concentration in water. Water can be ionized by the following reaction:H2O H+ + OH-Mathematically:pH = -log[H+]

What this means is that for every tenfold change in hydrogen ion concentration, there is a one unit change in pH. The pH scale is usually said to run from 1 to 14, though the pH of say, six molar sulphuric acid is less than zero.

In pure water, [H+] = [OH-] = 10-7 M. So the pH of pure water is pH 7. Adding acids or bases to water shifts this balance. Acids add H+, so adding acid raises the [H+] and lowers the pH. If we add just enough hydrochloric acid to pure water to bring the [H+] to 10-6 molar, what would the pH be?

The pH of water must be close to neutral (pH 7) for fish or other aquatic organisms to survive. Similarly, the pH of water in the pore spaces of soil must be close to 7. The soil pH may also affect the availability to plants of nutrients in the soil. Water with a low pH (below about 6.5) is corrosive to metal surfaces (eg, copper pipes, steel tanks).

Many lab tests require samples to be adjusted to a particular pH by adding a buffer. Likewise, media used to grow or assay microbes usually need to be adjusted to a certain pH range. A buffer is a solution that has a high ability to absorb acid or base without changing pH. Borate, citrate, phosphate, phthalate and other multivalent anions are often used to make buffer solutions. Buffers can be made quite precisely for calibrating pH measurements.

We measure pH using indicator dyes, pH test strips, or a pH meter. Dyes are organic compounds with absorbances in the visible range. Some of these, such that water supplied for drinking purpose has to undergo many processe such as neutralisation, precipitation , coagulation etc. All these processes ar are ph dependent. ph of natural water lies between 4.4-8.5.

For the determining the pH of a solution different methods are employed. the most widely used method is by using pH metre. the value of pH, the logrithm of the reciprocal of the hydrogen ion concentation in solution, is determined by measuring the difference in potential bwtween two electrode immersed in a sample soluion.the method based is based on the determination of the potential difference between an electrode pair consisting of a glass electrode sensutive tothe difference in the hydrogen ion activity in the sample solution and the internal filling solution,and a reference electrode, which is supposed to have a constant potential independent of the immersing solution. these days, combined electrodes are used in which the reference electrode is combined with a glass electrode. the measured potential difference is compared with the potential obtained when both elctrode are immersed in a solution or buffer with known pH or hydrogen ion concentration.

A chemical cell consisting of an acid-permeable glass membrane separating two solutions will develop a voltage related to the difference between the hydrogen ion activities in the two solutions. (Chemical activity is closely related to concentration). The voltage is related to the activities (or concentrations) by the Nernst equation:

E = E0 - (2.303RT/nF)log([H+]in/[H+]out)

where eare the electrode potential, r is the universal gas constant, t the absolute temperature and f is the faraday constant.

Conductivity

Conductivity is a measure of how well a solution conducts electricity. Water with absolutely no impurities (which really does not exist) conducts water very poorly. In real life, the impurities in water increase its conductivity. Because of this, if we measure the conductivity of water, we have some estimate of the degree of impurity. The current is actually carried almost entirely by dissolved ions. The ability of an ion to carry current is a functions of its charge and its mass or size: Ions with more charge conduct more current; larger ions conduct less.

To measure conductivity we use a machine called a conductivity meter. The actual amount of electricity that a given water solution will conduct changes with how far apart the electrodes are and what temperature the water is. This quantity is expressed in units called mhos (the unit of resistivity is the ohm; mho is ohm spelled backwards). The meter has a probe with two electrodes, usually 1 centimeter apart. Most of the modern ones sense the temperature as well and electronically correct for its effects. Since the meter gives a reading which is corrected for temperature and electrode separating distance, the number is called "specific conductance," expressed in mhos per centimeter at 25 C. The SI unit of conductivity is the siemen (S) named after the French physicist and equivalent to the mho. Thus 1 microsiemen per meter (mS/m) is equivalent to 100 mmho/cm. Very often, a meter will read out in mS/cm or mS/cm (or just mS or mS which are assumed to be per centimeter).

Laboratory pure water has a specific conductance of about one millionth of a mho/cm. What is the conductivity of our distilled water? Wells and lakes in Connecticut usually have a specific conductance of about 50 to 500 times that. To make these number easy to write, we usually use units of micromhos per centimeter (mmhos/cm). Thus laboratory pure water is around 1 mmho/cm; tapwater is usually around 50 to 500 mmhos/cm.

Procedure

Calibration of electrode as per the following procedure:Connect the pH metre to the pwer supply. switch on the instrument.Take a standard buffer solution of pH 7 in 100ml beaker. note the temperature of the buffer.Set the temperature control of the pH metre tot he temperature of the buffer solution.Remove the combination electrode from the storage solution, wash it with distilled water and blot dry with soft tissue paper.Connect the combination elctrode to the input socket and dip the electrode in 7 oh buffer solution.Set the function selector switch to pH position and adjust with 'calibrate' control till the digital display show the pH 7.Now move the fiunction switvh to 'stand by' position.Remove the electrode from the buffer solution and wash it with distilled water. dry with tissue paper.Dip the electrode in the buffer solution having pH 4.Set the "temperature" tothe temperature of the soluion.Set the function selector switch to pH position and adjust with 'slope correction' control till the digital display show the pH 4pH measurementConnect the combination electrode to yhe input socket after washing it with distilled water.Dip the combined electrode in the solution under test.Set the temperature knob to the temperature of the solution.Set the 'function selector switch' to pH position.Note the pH of the solution.Repeat the same procedure for other water samples.

Procedure to determine conductivityWash the conductivity cell thoroughly with distilled water.Rinse the conductivity cell repeatedly with kcl solution.Take the sufficient volume of kcl solution in a beaker and note down its temperature.Connect the instrument to the mains and switch on the instrument using the power switch. connect the electrode leads in the input socket at the rear of the instrument.Set the 'function switch' to 'check' position and adjust the displayto 1.000 with CAL control at the back panel.Dip the conductivity cell in kcl solution and adjust the temperature knob of the conductivity bridge at the conductivity bridge at the temperature of the kcl solution.Move the 'function' switch to 'conductance' position and range position to appropriate range.Adjust the cell constant knob so tht the display reads the known value of the kcl solution at that temperature.Bring the 'function switch' to 'cell constant' position and read the value of the cell constant from the display window.Take 100ml of the water sample and note its conductiviy.Similarly note the conductivity of all the samples.Experimental

ObservationsSheet1

AREApHconductitvity (mho/cm)

Tilak Nagar7.990.51

Krishna Nagar7.871.66

Kashmere Gate7.870.73

shivaji Nagar7.210.64

Gurgaon NCR7.940.69

Vasant Vihar7.070.15

Dwarka sector 57.724.42

Shahdara8.10.38

Lajpat Nagar8.010.39

Paschim Vihar7.970.5

Adarsh nagar80.76

North Delhi7.360.78

Netaji Nagar7.930.59

Dwarka 7.670.65

West Delhi 8.121.52

Central Delhi7.850.77

East Delhi6.80.47

North Delhi7.575.4

Paschim Vihar7.620.45

Dwarka sector 17.310.67

Dwarka sector197.980.42

RK Puram7.970.54

Shahdara7.940.52

rajuri garden(.e)7.530.265

anand vihar7.071.5

subash nagar7.120.74

kirti nagar7.040.942

dwarka sec-66.931

Paschim Vihar6.980.406

panchsheel7.160.456

dwarka(sec- 12)7.10.704

dwarka7.280.375

palam6.911

east of kailash7.250.201

munrka dda flats7.130.261

dilshad garden7.410.18

vasantkunj dda flats7.111.182

mehraul7.190.209

dwarka(sector-17)6.970.781

laxmi nagar7.210.198

pitampura7.370.278

govindpuri dda flats7.260.199

patparganj7.080.817

rohini7.041

mayur vihar7.120.017

shahdra7.10.192

Result and discussionThe observations of all drinking water samples collected from several distinct regions of Delhi-NCR with repect to the most important chemical parametres are presented in the table . most of the chemical parametres fell within the standard prescrubed values or using the select water purificatioon technologies, were successfully brought within permissible limits.The two main objective of this report were to analyse the drinking waer being supplied in the dwelling units of Delhi-NCR and to spread awareness among students about the need and importance of safe drinking water. Our project commenced on aspectic collection of water samplesfraom different Delhi-NCR region. students were asked to bring tap water samples from their homes followed by analyses of water by standard protocols.chemical parametres, such as, pH and conductivity of the collected samples of Delhi-NCR region are presented in the table above. the pH value of the regions like dwarka, shahdra, lajpat nagar, adarsh nagar lied between (8-8.5) which is very close to WHO limits (6.5-8.5) and are somewhat alkaline in anture.central delhi was rated much better than others with respect to pH and conductivity. pH of the water samples from paschim vihar, dwarka sec-17, panchsheel, dwarka sec-7, east delhi and palm vuhar was found to be a bit on acidic side with ph ph lying in the range of (6.5-6.9). the pH of all other regions satisfied the WHO set norms well with pH between (7.1-7.5).The electrical conductivity of water releates to the total concentration of dissolved ions.

Conductivity of most of the samples collected from different regions was found to lie between (maximum allowed limits is 1.055 mhos/cm). Conductivity of the regions like krishna nagar, anand vihar, west delhi, dwarka, vasant kunj lied between (1.0-1.5 mho/cm). conductivity of west delhi was found to be exceedind the permissible limits (1.52 mho/cm). Rest all regions' conductivity lied with the set norms.

Conclusion

It was relieving and resuring that the municipality treated drinking water supply across Delhi-NCR was found to be reasonably good quality, adequately treated and safe for comsumption. Chemical parametres pH and conductivity values of the MCD water supplies were found to be mostly within permissible limits.