water sample test
A REPORT ON
“PHYSIOCHEMICAL ANALYSIS OF GROUNDWATER AND SURFACE WATER SAMPLE
COLLECTED FROM DHULIKHEL”
SUBMITTED TO:
DEPARTMENT OF NATURAL SCIENCES(CHEMISTRY)
KATHMANDU UNIVERSITY
DHULIKHEL, KAVRE,
NEPAL.
SUBMITTED BY:
SUNIL BHATTARAI (03)
BASUDEV JOSHI (08)
DEPENDRA UPRETI (30)
DATE: 23rd DECEMBER 2010
Acknowledgement
We would like to express our sincere gratitude to the
department of chemistry for providing us the opportunity to conduct this
project. We also like to thank our supervisors Mr. Rajib Shrestha, Mr. Kuldeep
Chhetri for the proper guidance. We
would also like to thank the lab technicians who provided valuable help during
the work.
Abstract
In this project we brought ground and surface water sample from
Dhulikhel to test its quality and for which purpose this water can be used. We
studied many physical as well as chemical parameters of the water.
Physical Parameters: pH,
conductivity and temperature.
Chemical Parameters: Na, Cl, K, Fe++, Fe+++, NO2‾,
NO3‾, Po4, Mn, Cr, DO (Dissolved Oxygen). The value of
pH, Conductivity, temperature, CL, K, Fe++, Fe+++, NO2‾,
NO3‾, Po4, Mn, Cr, DO (Dissolved Oxygen) were found to
be:-
PH, A= 6.6 B=7.4
Conductivity A= 2.02milli siemen ,
B=1.64milli
siemen
Temperature, A=19oC B=18oC
Na, A= 30.1ppm B=30ppm
K, A=11.7ppm
B=32.4ppm
Fe++, A=0.785ppm B=0.885ppm
Fe+++, A=0.62ppm B=0.66ppm
NO2‾, A=0.08ppm B=0.247ppm
NO3‾,A=0.867ppm B=3.267ppm
DO, A= 5.33ppm B=9.6ppm
Hardness, A=11.2ppm B=8.2ppm
Chloride, A=31.694ppm B=37.691ppm
All the parameters are found
within the limits of WHO.
INTRODUCTION
Water is persistence for life. All living things depend absolutely
on supply of water. Water is mainly used for drinking, irrigation, household
purposes in our daily life.
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of litho logic formations. A unit of rock or an unconsolidated
deposit is called an aquifer when it can yield a usable quantity of water. The depth at which
soil pore spaces or fractures and voids in rock become completely saturated
with water is called the water table. Groundwater is recharged
from, and eventually flows to, the surface naturally; natural discharge often
occurs at springs and seeps, and can form oases or wetlands. Groundwater is also often withdrawn for agricultural, municipal and industrial use by constructing and operating extraction wells. The study of the distribution and movement of groundwater is hydrogeology, also called groundwater hydrology.
Typically, groundwater is thought of as liquid water flowing
through shallow aquifers, but technically it can also include soil moisture, permafrost (frozen soil), immobile water in very low permeability bedrock,
and deep geothermal or oil formation water. Groundwater is hypothesized to provide lubrication that can possibly influence the movement of faults. It is likely that much of the Earth's subsurface contain some
water, which may be mixed with other fluids in some instances. Groundwater may
not be confined only to the Earth.
We choosed Dhulikhel’s surface and
ground water for our project for analytical purpose to study physical and
chemical parameter. Pollution growth, urbanization, modernization the quality
of water is degrading day by day. Polluted water is the main cause of
degradation of water quality. Water pollution is a state of deviation from the
pure condition, whereby its normal function and properties are affected. Or,
water can be regarded polluted when it changes its quality or composition
either naturally or as a result of human activities, thus, becoming less
suitable for drinking , domestic, agricultural, industrial, recreational, wildlife
and other uses for which it would have been otherwise suitable in its natural
and unmodified state.
Sources
of water pollution:
The
common sources of water pollution can range from purely natural to several
anthropogenic activities like discharge of domestic and industrial waste water
etc. Some common sources of water
pollution are:
I.
Natural sources and run-off
II.
Domestic sewages and wastes
III.
Agricultural wastes
IV.
Industrial wastes
V.
Leaching
Water
can be regarded as polluted when it changes its quality of composition wither
naturally or as a result of human activities, thus becoming less suitable for
drinking, domestic, agricultural, industrial, industrial, recreational,
wildlife and other uses. Majority of water pollutants are however in the form
of chemicals which remain dissolved of suspended in water and give an
environmental response, which is not acceptable. These pollutants highly affect
human health along with other living organisms and also cause corrosiveness,
hardness, toxicity etc.
Due
to lack of access to clean water, each year millions of people around the world
are affected from water borne diseases and other diseases. In Nepal, there’s
lack of adequate supply of drinking water in many places and even the available
water is not safe enough due to the lack of proper treatment and contamination
during the distribution. The health profile of Nepal reveals a high incidence
of illnesses related to water, sanitation and personal hygiene. It is estimated
that 40 per 1000 causes of child morbidity and mortality is related to
water-borne diseases, contributing to 16.5% of deaths in infants. Drinking of
water quality in Kathmandu valley is clearly below international standards.
Thus,
the parameters like pH, conductivity,hardness, chloride, COD, DO of several
samples are tested so as to compare them with WHO standard and to know whether
they are suitable for any human uses.
These
parameters are specifically tested because:
- Temperature affects the chemical and biological reactions in water like its increment accelerated chemical reactions, reduce solubility of gases, elevate metabolic activity of organisms etc.
- DO is for higher aquatic diversity, the lesser DO may move away some sensitive aquatic animals.
- Chloride are not usually harmful to people but the sodium part of table salt has been linked to heart and kidney disease.
- Hardness is not health hazard but the hard water contributes a small amount toward calcium and magnesium human dietary needs.
- COD gives the measure of total quantity of oxygen required to oxidize all organic material into carbon dioxide and water.
- Leaching
HEALTH EFFECTS DUE TO
WATER POLLUTION
- Polluted water of river, ponds, and lakes harm the health of living beings including human beings.
- Polluted water causes several diseases such as diarrhoea, dysentery and typhoid.
- Polluted water if irrigated to agricultural land it affects young plants, seedlings, and living beings.
- Polluted water if used to clean vegetables, foods, fruits etc they carry germs and diseases with them and when we eat them we will suffer from various diseases.
Polluted
water generates bad smell to its surrounding. It pollutes the settlement area
and its environment
OBJECTIVES:
The
objective of the project is as follows:
ü To
collect water samples from a specified site of distribution of a water source.
ü To
test the water sample for various physical and chemical parameters like:
ü Color
and Odor
ü Turbidity
ü Temperature
ü Chemical
oxygen demand (COD),
ü Dissolved
metal and salts (sodium, chloride, potassium, calcium, manganese, magnesium)
etc.
ü To
compare the quality parameters of water sample from our specified site to those
of other sites of the same source collected by other groups so that we can find
out the level of pollution of the river at different sites during its
distribution.
ü To
identify the major pollutants in water.
The
site we had chosen for the sample collection was a small river from Dhulikhel,Kavre.
We
collected the second sample from the well which was around 10m away from the
river. It is a common well in the area and the people around the area come over
there to take water for several purpose.
The
various factors are decreasing the water quality of the river. Some of these
factors include:
1. Increasing population
2. Direct
disposal of untreated sewage into the river
3. Uncontrolled
sand mining
4. Improper solid waste disposal
5. Rapid
construction of industries
6. Uncontrolled
squatter settlement
7. Leaching
Water
quality is a term used to describe the chemical, physical, and biological
characteristics of water, usually in respect to its suitability for a
particular purpose. Assessment of the occurrence of chemicals that can harm
water quality, such as nutrients and pesticides in water resources, requires
recognition of complicated interconnections among surface water and ground
water, atmospheric contributions, natural landscape features, human activities,
and aquatic health. The vulnerability of surface water and ground water to
degradation depends on a combination of natural landscape features, such as
geology, topography, and soils; climate and atmospheric contributions; and
human activities related to different land uses and land-management practices.
Water quality is the
physical, chemical and biological characteristics of water, characterized
through the methods of hydrometry. The primary bases for such characterization
are parameters which relate to drinking water, safety of human contact and for
health of ecosystems.
Instrumentation
ANALYTICAL METHODS
2.2.1) SPECTROPHOTOMETRY
Fig: -
Spectrophotometer
fig: - schematic diagram
A spectrophotometer consists of
two instruments, namely a spectrometer for producing light of any selected color
(wavelength), and a photometer for measuring the intensity of light. The
instruments are arranged so that liquid in a cuvette can be placed between the
spectrometer beam and the photometer. The amount of light passing through the
tube is measured by the photometer. The photometer delivers a voltage signal to
a display device, normally a galvanometer. The signal changes as the amount of
light absorbed by the liquid changes. If development of color is linked to the
concentration of a substance in solution then that concentration can be
measured by determining the extent of absorption of light at the appropriate wavelength. For
example hemoglobin appears red because the hemoglobin absorbs blue and green
light rays much more effectively than red. The degree of absorbance of blue or green
light is proportional to the concentration of hemoglobin.
When monochromatic light (light
of a specific wavelength) passes through a solution there is usually a
quantitative relationship (Beer's law) between the solute concentration and the
intensity of the transmitted light, that is,
I=IO*10-kcl
where I sub 0 is the intensity
of transmitted light using the pure solvent, I is the intensity of the
transmitted light when the colored compound is added, c is concentration of the
colored compound, l is the distance the light passes through the solution, and
k is a constant. If the light path l is a constant, as is the case with a
spectrophotometer, Beer's law may be written,
I/IO=10-kc=T
where k is a new constant and T
is the transmittance of the solution. There is a logarithmic relationship between
transmittance and the concentration of the colored compound. Thus,
-log T= log 1/T=
kc =optical density
The O.D. is directly
proportional to the concentration of the colored compound. Most
spectrophotometers have a scale that reads both in O.D. (absorbance) units,
which is a logarithmic scale, and in % transmittance, which is an arithmetic
scale. As suggested by the above relationships, the absorbance scale is the
most useful for colorimetric assays.[2]
Ultraviolet-visible spectroscopy
The most common
spectrophotometers are used in the UV and visible regions of the spectrum, and
some of these instruments also operate into the near-infrared region as well.
Visible region 400–700 nm
spectrophotometry is used extensively in colorimetry science. Ink
manufacturers, printing companies, textiles vendors, and many more, need the
data provided through colorimetry. They take readings in the region of every
10–20 nanometers along the visible region, and produce a spectral reflectance
curve or a data stream for alternative presentations. These curves can be used
to test a new batch of colorant to check if it makes a match to specifications
e.g., iso printing standards.
Traditional visual region
spectrophotometers cannot detect if a colorant or the base material has
fluorescence. This can make it difficult to manage color issues if for example
one or more of the printing inks is fluorescent. Where a colorant contains
fluorescence, a bi-spectral fluorescent spectrophotometer is used. There are
two major setups for visual spectrum spectrophotometers, d/8 (spherical) and
0/45. The names are due to the geometry of the light source, observer and
interior of the measurement chamber. Scientists use this machine to measure the
amount of compounds in a sample. If the compound is more concentrated more
light will be absorbed by the sample; within small ranges, the Beer-Lambert law
holds and the absorbance between samples vary with concentration linearly. In
the case of printing measurements two alternative settings are commonly used-
without/with uv filter to control better the effect of uv brighteners within
the paper stock.
2.2.2) Flame
Photometry
Fig: -
Compressor unit
Fig: - Flame Photometry
Fig: - schematic diagram of flame photometry
Flame photometry is an atomic
emission method for the routine detection of metal salts, principally Na, K,
Li, Ca, and Ba. Quantitative analysis of these species is performed by
measuring the flame emission of solutions containing the metal salts. Solutions
are aspirated into the flame. The hot flame evaporates the solvent, atomizes the metal, and excites a valence electron to an upper
state. Light is emitted at characteristic wavelengths for each metal as the
electron returns to the ground state. Optical filters are used to select the
emission wavelength monitored for the analyte species. Comparison of emission
intensities of unknowns to either that of standard solutions, or to those of an
internal standard, allows quantitative analysis of the analyte metal in the
sample solution.
Flame
photometry is a simple, relatively inexpensive, high sample throughput method
used for clinical, biological, and environmental analysis. The low temperature
of the natural gas and air flame, compared to other excitation methods such as
arcs, sparks, and rare gas plasmas, limit the method to easily ionized metals.
Since the temperature isn't high enough to excite transition metals, the method
is selective toward detection of alkali and alkali earth metals. On the other
hand, the low temperatures renders this method susceptible to certain
disadvantages, most of them related to interference and the stability (or lack
thereof) of the flame and aspiration conditions. Fuel and oxidant flow rates
and purity, aspiration rates, solution viscosity, concomitants in the samples,
etc affect these. It is therefore very important to measure the emission of the
standard and unknown solutions under conditions that are as nearly identical as
possible.
This experiment
will serve as an introduction to sodium analysis by flame emission photometry
and will demonstrate the effects of cleanliness and solution viscosity on the
observed emission intensity readings. The instrument is calibrated with a series of standard solutions that cover the range of concentrations
expected of the samples. Standard calibrations are commonly used in
instrumental analysis. They are useful when sample concentrations may vary by
several orders of magnitude and when the value of the analyte must be known
with a high degree of accuracy. This experiment does not produce hazardous
waste.[3]
2.2.3)
Titration
It is the
normal titration method in which first of all the volume of analyte used is
observed and then the calculation is done by using stoichiometric relation.
Discussion
ANALYSIS OF DIFFERENT PHYSIO-CHEMICAL
PARAMETERS of the sample and obtained Results
Physical
parameters:
Colour:
Observation of the
colour of the water sample was done in the laboratory by direct observation
Temperature:
Temperature is the degree
of hotness ro coldness og the body ans is one of the most important factor to
be measured for the assessment of water quality.
Chemical parameters:
Total
Suspended solids (TSS):
1) 100
ml of the sample taken.
2) Filtration
through Whatmann’s 4-D filter paper was done.
3) Gravimetric
method of analysis.
Total Dissolved solids (TDS):
1) The
filtrate of the water sample taken in the porcelain basin.
2) Gravimetric
method of analysis was used.
Dissolved
oxygen:
Dissolved oxygen is the amount of
gaseous oxygen dissolved in water which is readily available for aquatic
organism as well as fishes. DO is important for aquatic diversity. if amount of
DO decrease then there will be less aquatic organism in water, they move away,
weaken or die.
Fresh water contains nearly 250 ppm
of oxygen. More dissolved Oxygen less polluted is the water and vice versa.
Chemical
oxygen demand:
Chemical
oxygen demand is the method of determining the organic load og water which is
biological oxygen demand.it is based on the chemical oxidation of material in
the presence of catalyst by cr2o7—in 50% sulphuric acid.
Most
of the organic matter decomposes and produces CO2 and H2O when boiled with a
mixture of potassium dichromate and sulphuric acid. A sample is refluxed with a
known amount of potassium dichromate in sulphuric acid medium and the excess of
dichromate is titrated against ferrous ammonium sulphate. The amount of
dichromate consumed is proportional to the oxygen required to oxidize the organic
matter.
Chromium (Cr) and Manganese (Mn):
Determination by UV spectrophotom
Sodium (Na) and Potassium (K):
Determination
by using flame photometer.
Iron(II):
Determination
by 1, 10-Phenonthralin method
Chloride ions(Cl-)
·
5 ml of sample was taken in porcelain
basin and it was diluted to about 25ml with water
·
5 to 6 drpos of k2cr2o4 was added
·
Titration with standard sliver nitrate
solution was done till the brick red tinge appeared.
SAMPLE COLLECTION, PRESERVATION AND
SAMPLING SITE SELECTION
·
The survey is for the identification of
existing situation of water quality of a particular site. Water sample was
collected from dhulikhel river and ground water nearby.
·
The water sample was collected in
bottles at the site of collection.
·
The collected water sample was brought
in the lab maintaining minimal chemical changes as far as possible. The minimal
chemical change was maintained with the help of preservatives.
The
chemicals we used as preservatives are as follows:
|
Chemicals
|
Used
for analysis of
|
|
Mercuric
chloride (Hg2Cl2 )
|
Nitrate
, Phosphate, Nitrite
|
|
Sulphuric
acid (H2SO4 )
|
Dissolved
oxygen, chemical oxygen demand
|
|
Nitric
acid (HNO3)
|
Hardness,
metal ions
|
Standard
values of the water quality parameters as given by WHO
|
S.N
o
|
Parameters
|
Standards
|
|
1.
|
Dissolved
Oxygen
|
No
guidelines
|
|
2.
|
Chemical oxygen demand
|
No guidelines
|
|
3.
|
Iron
|
1
mg/l
|
|
4.
|
Nitrate
(NO3)
|
50
mg/l
|
|
5.
|
Nitrite
(NO2)
|
50
mg/l
|
|
6.
|
Manganese
(Mn)
|
0.5
mg/l
|
|
7.
|
Chromate
(Cr)
|
0.05
mg/l
|
|
8.
|
Phosphate
|
|
|
9.
|
Potassium
|
1.2mg/l
|
|
10.
|
Sodium
(Na)
|
200
mg/l
|
|
11.
|
Chloride
ions
|
250
mg/l
|
EXPERIMENTAL SECTION
PHYSICAL PARAMETERS
The
water sample was taken from surface and ground water sources in dhulikhel,
Kavre.
The
different physical parameters of the water were measured and following results
were obtained:
For
surface water:
·
Temperature:200 C
·
Turbidity: clear
·
Conductance:
·
Ph:
For
ground water:
·
Temperature:240c
·
Turbidity: clear
·
Conductance:79
·
Ph:5.04
MEASURING TOTAL
SUSPENDED SOLIDS AND TOTAL DISSOLVED SOLIDS
50
ml of water sample was taken. The weight of the filter paper was taken as w1
and the weight of the porcelain basin was taken to be w2.The water
sample was filtered and the filtrate was dried by the help of a Bunsen burner
to obtain the dissolved solid. The weight of the dry mass was taken to be w3.The
dry weight of the filter paper was w4.So,
w3-w2=
dissolved solid
w4-w1=
suspended solids
Observation:
|
Source
|
Surface
water
|
Ground
water
|
|||
|
|
W1(gm)
|
W2(gm)
|
W1(gm)
|
W2(gm)
|
|
|
Total
suspended particles
|
0.95
|
0.94
|
0.92
|
0.94
|
|
|
Total
dissolved solids
|
54.71
|
54.72
|
82.01
|
82.05
|
|
CALCULATION:
For
surface water:
TDS=
W2-W1
=
54.72-54.71
=
0.01 gm
TSS=
W2-W1
=
0.94-0.92
=
0.02 gm
For
ground water:
TDS= W2-W1
= 82.05-82.01
=0.04 g
TSS= W2-W1
= 0.94-0.92 =0.02
TO
DETERMINE THE DISSOLVED OXYGEN (DO) PRESENT IN GIVEN WATER SAMPLE.
Dissolved
oxygen is an index of physical and biological process going on in water. Non
polluted water is normally saturated with dissolved oxygen, which contains near
250 ppm of 02.The more the dissolved oxygen the less is the polluted
water. There are two main source by which water can get dissolved oxygen i.e.
diffusion from air and photosynthetic activities within water.
Diffusion
oxygen from air to water is physical phenomenon and is influenced by factors
which affect the oxygen solubility like temperature, water movements and
salinity etc. Photosynthetic activity is a biological process carried out by
autotrophs and depends on autotrophic population, light condition sand
available gases etc.
Reactions
involved:
MnSO4
+ KOH →→→Mn (OH) 2 + K2SO4
2Mn
(OH) 2 +O2 →→→ 2MnO (OH) 2
MnO
(OH) 2 +H2SO4 →→→ MnSO4 + 2H2O
+O
2KI
+ H2SO4 +O→→→ K2SO4 + H2O
+ I2
I2
+ 2 Na2S2O3 →→→ Na2S4O6
+2 NaI
From
equations:
1
mole of Na2S2O3
= 1 mole of I2 = 1 mole of O = 1 mole of MnO(OH)2 = ½ mole of O2.
i.e.
2 mole of Na2S2O3 = ½ mole of O2
1
mole of Na2S2O3 = ¼ mole of O2
Materials
and reagents required:
v BOD
bottles (150 ml)
v Manganous
sulphate solution
v Alkaline
Potassium iodide solution
v Sodium
thiosulphate solution ( 0.025M )
v Starch
indicator
v Conc.
H2SO4 ( sp. gravity 1.84,18M )
Procedure:
1) Fill
the BOD bottles with sample water without any bubbling.
2) Add
1 ml each of Manganous sulphate and alkaline Potassium Iodide solution , so
that some precipitation occurs.(shake)
3) Further
add 2 ml of concentrated H2SO4 to dissolve the ppt.
4) Pipette
out 100 ml of sample. Add 1 ml of starch and titrate with 0.005 M Na2S2O3
solution ( standardize using standard K2Cr2O7)
Dissolved
Oxygen (DO):
|
S.N
|
Sample
source
|
Volume
of sample(ml)
|
Initial
reading(ml)
|
Final
reading(ml)
|
Difference(ml)
|
Concurrent
reading(ml)
|
|
1
|
Surface
water
|
25
|
0
|
1.9
|
1.9
|
1.9
|
|
2
|
Ground
water
|
25
|
1.9
|
2.5
|
0.6
|
0.6
|
Calculation:
N1V1=
N2V2
1/100*V1=100*N2
N2=V1/10000
So,
Strength
of dissolved oxygen (DO) = N2*equivqlent weight
(surface
water) = V1/10000*8gm/l
=V1/10000*8*1000
=0.8V1
ppm
=
0.8*1.9 ppm =1.52 ppm
Strength
of dissolved oxygen (DO) = N2*equivqlent weight
(ground
water) = V1/10000*8gm/l
=V1/10000*8*1000
=0.8V1
ppm
=
0.8*0.6 ppm =0.48 ppm
Results:
DO in surface water=
1.52ppm
DO in ground water=0.48ppm
DETERMINATION OF SODIUM
BY USING FLAME PHOTOMETER
Flame
photometry is based on the fact that compounds of alkali and alkaline earth
metals can be thermally excited in a low temperature flame and when the atoms
return to the ground state they emit radiation which lies mainly in the visible
region of the spectrum. Each element emits radiation at a wavelength specific
to that element. E.g. 589nm, K 766nm, Ca 622nm, Li 670.8nm, etc.
Over
a certain range of concentration the intensity of the emitted radiation is
directly proportional to the number of atoms returning to the ground state.
This in turn is proportional to the absolute quantity of the species volatized
in the flame i.e. light emitted is proportional to the sample concentration.
The light emitted by the element at its characteristics wavelength is isolated
by an optical filter and the intensity of that light is measured by photo
detector which provides a signal proportional to the sample concentration. Such
an electrical signal is processed with the help of analog to digital converter
and the microprocessor.
Procedure
1) Prepare
standard solutions of sodium chloride (1 ans 100 ppm respectively)
2) Determine
the concentration of sodium in the given sample using flame photometer which directly
provides the required value.
Sample:
Surface
water = 8.7ppm
Ground
water = 8.4ppm
Result:
The
concentration of sodium was found out to be
8.7ppm in the surface water while in ground water is 8.4ppm.
DETERMINATION OF
CHLORIDE IONS PRESENT IN SAMPLE
Theory:
Chlorine
occurs naturally with metal. It is present as negative ions i.e. Cl-.The
commonest chloride compound is sodium chloride, which occurs in sea water and
rock salt. Each kilogram of sea water contains about 30 g of sodium chloride.
Chlorine is used as a cheap oxidant in the manufacture of bromine. It is also
used in the manufacture of many familiar materials like hydrogen chloride.
Chlorine compounds have been developed as degreasing solvents such as
tetrachloromethane and trichloroethane,as, as plastics such as PVC, as
disinfectants such as dettol and as pesticides like DDT, BHC etc. Chlorides are
determined by titration with Silver nitrate.
Procedure:
Standardization
0f AgNO3 solution
Pipette
out 10 ml of standard 0.005 NaCl solutions into 250ml conical flask resting on
a white title. Add 1 ml of 5% K2CrO4 indicator. Add AgNO3
solution slowly from the burette, while stirring the liquid constantly, until
the reddish borwn ppt formed by the
addition of each drop begins to disappear more slowly. This indicates the
approach the end point. Continue the
addition of AgNO3 solution slowly, drop by drop, until the solution
assumes a faint but distinct reddish brown colour which persists even after
shaking the solution briskly. This marks the end point. Note the confirmed
titration value.
Indicator
blank correction
Determine
the indicator blank correction by adding 1 ml of the indicator to volume of
distilled water equals to that of the final volume in the titration and then
titrating with silver nitrate as described above. The indicator blank
correction, which should not be more than about 0.1 ml, should be deducted from
each titrated value.
Titration
with test sample
Add
Transfer 50ml of the water sample into a 250ml conical flask ,added 1ml of K2CrO4
indicator and titrate against AgNO3( 0.005M) solution slowly
,drop by drop, until the solution assumes a faint but distinct reddish brown
colour, which persists even after shaking the solution briskly. This marks the
end point. Note the confirmed titrated reading.
Chloride:
|
S.N
|
Sample
source
|
Volume
of sample (ml)
|
Initial
reading(ml)
|
Final
reading(ml)
|
Difference(ml)
|
Concurrent(ml)
|
|
1
|
Surface
water
|
50
|
0
|
7.7
|
7.7
|
7.7
|
|
2
|
Ground
water
|
50
|
0
|
7.3
|
7.3
|
7.3
|
Calculation:
For river:
100
ml of 0.001M AgN03 contains 0.001 moles
1
ml of 0.001M AgN03 contains 0.001/100 moles
0.4
ml of 0.01M AgN03 contains 0.01/1000 *0.4 moles =4*10^-6 moles
And,
No
of moles of chloride ion = 4*10^-6
We
know,
50
ml of sample contains 4*10^-6 moles of chloride ion
1
ml of sample contains 4*10^-6/25 moles of chloride ion
1000
ml of sample contains 4*10^-6/25 *1000 moles of chloride ion =1.6*10^-4 moles
=
1.6*10^-4*7.7
=
5.68*10^-3 gm
=
5.68 mg
The
concentration of the chloride ion in the sample = 5.68 ppm
For tube well:
1000
ml of 0.01M AgN03 contains 0.01 moles
1
ml of 0.01M AgN03 contains 0.01/1000 moles
0.4
ml of 0.01M AgN03 contains 0.01/1000 *0.3moles = 3*10^-6moles
And,
No
of moles of chloride ion = 3*10^-6
We
know,
25
ml of sample contains 3*10^-6 moles of chloride ion
1
ml of sample contains 3*10^-6/25 moles of chloride ion
1000
ml of sample contains 3*10^-6/25 *1000 moles of chloride ion =1.2*10^-4 moles
=
1.2*10^-4*35.5
=
4.26*10^-3 gm
=
4.26 mg
DETERMINATION OF
POTASSIUM BY USING FLAME PHOTOMETER
Flame
photometry is based on the fact that compounds of alkali and alkaline earth
metals can be thermally excited in a low temperature flame and when the atoms
return to the ground state they emit radiation which lies mainly in the visible
region of the spectrum. Each element emits radiation at a wavelength specific
to that element. E.g. 589nm, K 766nm, Ca 622nm, Li 670.8nm, etc.
Over
a certain range of concentration the intensity of the emitted radiation is
directly proportional to the number of atoms returning to the ground state.
This in turn is proportional to the absolute quantity of the species volatized
in the flame i.e. light emitted is proportional to the sample concentration.
The light emitted by the element at its characteristics wavelength is isolated
by an optical filter and the intensity of that light is measured by photo
detector which provides a signal proportional to the sample concentration. Such
an electrical signal is processed with the help of analog to digital converter
and the microprocessor.
Procedure
1) Prepare
standard solutions of potassium chloride (1 ppm and 100 ppm respectively)
2)
Determine
the concentration of potassium in the given sample using flame photometer which
directly provides the required value.
Surface
water=1ppm
Ground
water=3ppm
Result:
The
concentration of potassium in surface water was found to be 1 ppm while the
concentration in the ground water was found to be 3 ppm
SPECTROPHOTOMETRIC
DETERMINATION OF IRON CONTENT IN SUPPLIED IRON(III) SOLUTION
Iron
(III) reacts with thiocyanate to give a series of intensely red-colored
compound, which remain in true solution. Iron (III) does not react. Depending
upon the thiocyanate concentration ,a series of complexes can be obtained;
these complexes are red colored and can be formulated as [Fe(SCN)]2+,at
0.1M thiocyanate concentration it is largely [Fe(SCN)2]+,
and at very high thiocyanate concentration it is [Fe(SCN)2]3-.In
colorometric determination a large excess of thiocyanate should be used, since
this increases the intensity and also the stability of the colour. Strong acids
(hydrochloric or nitric acid concentration 0.05-0.5M) should be present to
suppress the hydrolysis.
Fe3+
+ 3 H20------Fe (OH)3 +3H+
Procedure:
1)
Prepare the following solutions
a) Standard
iron (III) ion solution. Dissolve 0.864 g ammonium iron (III) sulphate in
water, add 100 cm3 conc. HCL and dilute to 1 dm3. 1 cm3
of this solution contains 0.1mg of Fe.
b) Potassium
thiocyanate solution: Dissolve 20g potassium thiocyanate in 100 cm3
water. (2M ammonium thiocyanate solution can also be used).
2)
Take 25cm3 of standard iron
(III) ion solution in 50cm3 volumetric flasks, add 5 cm3 of
the thiocyanate solution and 3 cm3 of 4M nitric acid. Add distilled
water to the mark. Follow similar procedure for the sample also. Prepare the
blank solution using the same quantities of reagents except iron (III) ion
solution. Dilute the measured portions of standard iron (III) thiocyanate
solution with distilled water to prepare five solutions of different
concentrations.
3) Determine
the absorbance of different standard solution and sample solutions of iron
(III) at 480nm.Plot the absorbances against concentrations of the solution,
i.e. calibration curve. Determine the concentration of iron (III) in solution.
|
S.no
|
Concentration(M)
|
Absorbance
|
|
1.
|
0ppm
|
0
|
|
2.
|
10ppm
|
0.336
|
|
3.
|
20ppm
|
0.600
|
|
4.
|
30ppm
|
0.779
|
|
5.
|
40ppm
|
1.039
|
|
6.
|
50
ppm
|
1.403
|
|
7.surface
water
|
0.67
|
0.143
|
|
8.ground
water
|
0.47
|
0.101
|
Graph:
Calculation:
The
absorbance of the given unknown solution for surface water is 0.143
and
the absorbance for ground water is 0.101
From
the graph, the concentration of unknown solution of surface water is 0.67 ppm
and ground water is 0.47 ppm.
SPECTROPHOTOMETRIC DETERMINATION OF
THE AMOUNT OF IRON(II) IN SUPPLIED SOLUTION BY 1,10-PHENONTHRALINE METHOD
Procedure
1) Prepare
following solutions:
a) 1, 10-phenonthraline: 0.25%
solution of the monohydrate in water.
b)
0.1M sodium acetate and 0.1M acetic acid (glacial acetic acid is 1.7M approx.)
c)
Hydroxyl ammonium chloride: 10% aqueous solution.
d)
Buffer: Mix 65ml of 0.1M acetic acid and 35ml of 0.1M sodium acetate
e)
Standard iron (II) solution (0.1mg/ml): Dissolve calculated amount of
Mohr’s salt in distilled water.
You need about 50ml of this solution. Dilute this solution so as to obtain
solutions of five different concentrations of the range 0.1-0.5 mg of iron/10ml of solution.
2) Take
10ml of standard iron (II) solution (containing not more than 0.5mg of
iron) in a 50ml volumetric flask, add
5ml of hydroxyl ammonium chloride (10%) solution, add acetate buffer to
maintain the Ph around 4.5-4.7(note the require volume of buffer).Add 4ml of 1,
10-Phenonthraline solution, dilute to 50ml, shake the solution and measure the
absorbance (at 515nm) after 5-10 minutes using proper blank solution. Measure
the absorbance of other standard solution and supplied solution in similar way. Determine
the amount of iron (II) in supplied solution
from calibration curve.
|
S.NO
|
Concentration
|
Absorbance
|
|
1.
|
0
|
0
|
|
2.
|
1
|
0.231.
|
|
3.
|
5
|
0.901
|
|
4.
|
10
|
1.436
|
|
5.
|
15
|
1.467
|
|
6.
|
20
|
2.613
|
|
7.Surface water
|
1.34
|
0.167
|
|
8.ground water
|
0.69
|
0.0868
|
Graph:
Result:
The
absorbance of the given unknown solution for surface water is 0.167
And
the absorbance for ground water is 0.0868
From
the graph, the concentration of unknown solution of surface water is 1.34 ppm
and ground water is 0.69ppm
DETERMINE THE AMOUNT OF
PHOSPHORUS AS PHOSPHATE IN SUPPLIED SOLUTION
Procedure
1) Prepare
the following solutions:
a) Ammonium
molybdate solution: Solution 1.Dissolve 2.5gm of ammonium molybdate in 17.5ml
of distilled water. Solution 2: Add 28ml of conc.H2SO4 to
40ml of distilled water and cool. Mix two solutions 1 and 2 and dilute to
100ml.
b) Stannous
chloride solution (2.5g/100ml of glycerol).Mix required amount of stannous
chloride in 20ml of glycerol by heating on a water bath for rapid dissolution.
c) Standard
Phosphate solution (10mg of P/litre).Dissolve 5.03 gm of potassium dihydrogen
phosphate in distilled water and make up the volume to 1 litre.Dilute a portion
of this solution 100 times to prepare 500ml of final (stock) solution. The
final solution will be 10mg of phosphorus/litre.
2)
Prepare 50ml of standard phosphate solution of various dilutions having
Concentrations in the range of 0.1-1.0mg
P/litre at the interval of 0.1 by diluting
the standard phosphate
solution(10mgP/litre).Add 2ml of ammonium molybdate
followed by 5 drops of SnCl2
solution. Take the reading (at any fixed time after 5
minutes and before 12 minutes of the
addition of last reagent) at 688nm.
3) To
50ml of clear sample taken in conical flask add 2ml of ammonium molybdate
followed by 5 drops of SnCl2 solution. Take the absorbance reading
at 690nm.
4) Plot
calibration curve and determine the concentration of the supplied solution.
|
S.no
|
Concentration
|
Absorbance
|
|
1
|
0
|
0.
|
|
2
|
1
|
0.128
|
|
3
|
2.5
|
0.141
|
|
4
|
5
|
0.101
|
|
5
|
10
|
0.106
|
|
6
|
20
|
0.095
|
|
7.surface
water
|
13.243
|
0.098
|
|
8.ground
water
|
16.89
|
0.125
|
Graph:
Result:
The
absorbance of the given unknown solution for surface water is 0.098
and
the absorbance for ground water is 0.125
From
the graph, the concentration of unknown solution of surface water is 13.243 ppm
and ground water is 16.89 ppm
TO DETERMINE THE CONCENTRATION OF
NITROGEN AS NITRATE IN WATER SAMPLE(POTASSIUM NITRATE SOLUTION) BY USING
UV-VISIBLE SPECTROPHOTOMETER
Potassium
nitrate is an example of an inorganic compound which absorbs mainly in the
ultra violet, and can be employed to obtain experience in the use of manually
operated UV\Visible spectrophotometer. We can use automatic recording
spectrophotometer also.
The
absorbance and the % transmission of an approximately 0.1M potassium nitrate
solution are measured over the wavelength of 304nm.
The
three normal means of presenting the spectrophotometric data are described as
below. By far the most common procedure is to plot absorbance against
wavelength (in nm).The wavelength corresponding to the absorbance maximum (or
minimum transmission) is to read i.e. (302.5 to305nm, here we supposed to be
304nm).This wavelength is used for the preparation of calibration curve. This
point is chosen for 2 reasons:
1) It
is the region in which the greatest difference in the absorbance between any
different concentrations will be obtained, thus giving the maximum sensitivity
for concentration studies.
2) As
it is turning point on the curve it gives the least alternation in the
absorbance value for any slight variation in wavelength.
No
general rule can be given concerning the strength of the solution to be
prepared, as this will depend upon the spectrophotometer used for the study
.Usually a 0.01M to 0.001M solution is sufficiently concentrated for the
highest absorbance, and other concentrations are prepared by dilution. The
concentration should be selected such that the absorbance lies between 0.3 to
1.5.For the determination of the concentration of the substance select the
wavelength 304nm and construct the calibration curve by measuring the
absorbance of 4-5 concentrations of the substance( e.g. 2,4,6,8,10 gm KNO3
L-1) at the selected
wavelength .Plot the absorbance (ordinates) against the concentration
(abscissa). If the compound obeys the Beer’s law, a linear calibration curve
passing through the origin, will be obtained. If the absorbance of the unknown
solution is measured the concentration can be obtained from the calibration
curve.
If
it is known that the compound obeys Beer’s law the molar absorption coefficient
E can be determined of the absorbance of a standard solution. The unknown
concentration is then calculated using the value of the constant E and the
measured value of the absorbance under the same conditions.
Procedure:
Dry
some pure potassium nitrate at 110oc and cool in the
desiccator.Prepare an aq. Solution containing 10gl-1.With the aid of
a precision spectrophotometer and matched 1cm rectangular cell plot the data of
absorbance against wavelength.
Use
the value of the wavelength to determine the absorbance of solutions of
potassium nitrate solution containing 2, 4, 6, and 8 g of potassium nitrate per
litre. Plot the absorbance (ordinate) against concentration (abscissa).Determine
the absorbance of an unknown solution of potassium nitrate and read the concentration from the
calibration curve.
|
S.no
|
Concentration
|
Absorbance
|
|
1.
|
0.2
|
0.608
|
|
2.
|
0.4
|
0.818
|
|
3.
|
0.6
|
0.953
|
|
4.
|
0.8
|
1.115
|
|
5.Surface
water
|
0.31
|
0.497
|
|
6.ground
water
|
0.34
|
0.547
|
Graph:
:
Result:
The
absorbance of the given unknown solution for surface water is 0.497
and
the absorbance for ground water is 0.547
From
the graph, the concentration of unknown solution of surface water is 0.31 ppm
and ground water is 0.34 ppm.
DETERMINE THE AMOUNT OF NITROGEN AS
NO2- IN SUPPLIED
SOLUTION
Procedure:
1)
Prepare 100ml each of:
a) EDTA
solution (5.0mg/ml) taking calculated amount of disodium salt EDTA in distilled
water.
b) Sulphanilic
acid (6.0mg/ml in 20% HCL(v/v) by dissolving required amount of Sulphanilic acid in a solution already
containing 20ml of conc. HCL in 70ml of water. Make the volume up to 100ml.
c) 1-naphaathylamine
hydrochloride (6.0mg/ml in 1% HCL(v/v) by dissolving calculated amount of the
substance in about 50ml of water containing 1ml of conc.HCL.Dilute the solution
to 100ml.Filter the solution if precipitates occur.
2)
Prepare 100ml of the standard nitrite solution having the concentration of the
range 0.1-1.0 mg/litre NO2-N at interval of 0.1.Take 50ml of
standard NO2- in a conical flask ,add 1ml of each –EDTA,Sulphanilic
acid ,1-naphthylamine hydrochloride and sodium acetate solution in sequence.
Also prepare blank solution.
3)
A Wine red colour will appear in presence of nitrites. Wavelength of 304m was
fixed for the absorbance reading the
process was repeated for other standard solutions and sample solution.
4) the
calibration curve was plotted and the concentration of nitrite was determined.
|
S.no
|
Volume(ml)
|
Absorbance
|
|
1
|
20
|
0.608
|
|
2.
|
40
|
0.818
|
|
3.
|
60
|
0.953
|
|
4.
|
80
|
1.115
|
|
5.surface water
|
37.79
|
0.601
|
|
6.ground water
|
32.26
|
0.513
|
Graph:
Results:
The
absorbance of the given unknown solution
for surface water is 0.601 and that of ground water is 0.513
From
the graph, the concentration of unknown solution
For
surface water is (37.79*2)is 75.58 ppm
Ground
water is (32.26*2) is 64.52 ppm.
SIMULTANEOUS SPECTROPHOTOMETRIC DETERMINATION OF CHROMIUM AND MANGANESE
This
is concerned with the simultaneous determination of two solutes in a solution.
For manganate, the absorption peak is at 545 nm where as for dichromate, it is
440 nm.
Reagents:
Potassium dichromate: 0.002 M,0.004 M,0.006 M and 0.008 M in 1M H2SO4 and
0.7 M
Phosphoric acid, prepared from the
analytical reagents.
Potassium permagnate: 0.001M, 0.002M,0.003M, and 0.004M in 1M H2SO4
and 0.7 M
Phosphoric acid, prepared from the
analytical reagents.
All flasks should be scrupulously
clean.
Procedure:
For manganate:
Mix 1M concentrated sulphuric acid
with 0.7M phosphoric acid and make a solution of 1 litre. Then, take 0.01M
potassium permanganate and with the help of the solution made before, dilute it
to make the concentration of 0.002M, 0.004M, 0.006M and 0.008M.In this case,
the blank used is the same solution of 1M concentrated sulphuric acid with 0.7M
phosphoric acid. Now, with these five solutions, make the standard curve for
magnitude at 545nm.Again, for the determination of manganate in sample, mix
phosphoric acid and concentrated sulphuric acid with the sample to make it up
to 100ml. Finally, measure the absorbance of the sample.
Table:
|
S.no
|
Concentration(M)
|
Absorbance
|
|
1.
|
0
|
O
|
|
2
|
0.002
|
0.49
|
|
3.
|
0.004
|
0.85
|
|
4
|
0.006
|
1.25
|
|
5
|
0.008
|
1.67
|
|
7.surface
water
|
0.0042
|
0.890
|
|
8
ground water
|
0.0004s
|
0.082
|
Graph:
Result:
The absorbance of the given unknown
solution
Surface water=0.901
Ground water=0.087
From the graph, the concentration of
unknown solution
surface water=
ground water=
For chromate:
Mix 1M concentrated sulphuric acid
with 0.7M phosphoric acid and make a solution of 1 litre. Then, take 0.01M
potassium dichromate and with the help of the solution made before, dilute it
to make the concentration of 0.001M, 0.002M, 0.003M, and 0.004M. In this case,
the blank used is the same solution of 1M concentrated sulphuric acid with 0.7M
phosphoric acid. Now with these five solutions, make the standard curve for
dichromate at 440nm. Again, for the sample, mix phosphoric acid and
concentrated sulphuric acid with the sample to make it up to 100ml. Finally,
measure the absorbance of the sample
Table:
|
s.no
|
Concentration(M)
|
Absorbance
|
|
1
|
0
|
0
|
|
2
|
0.001
|
0.394
|
|
3
|
0.002
|
0.877
|
|
4
|
0.003
|
1.324
|
|
5
|
0.004
|
1.726
|
|
6.surface
water
|
0.00037
|
0.163
|
|
7
ground water
|
0.00033
|
0.146
|
Graph:
Result:
The absorbance of the given unknown
solution for Surface water is 0.163
And Ground water 0.146
From the graph, the concentration of
unknown solution
Surface water is 0.0037
Ground water is 0.00033
RESULTS AND DISCUSSION
|
S.N
|
Parameter
|
Surface water
Concentration(ppm)
|
Ground water
Concentration(ppm)
|
|
|
DO
|
|
|
|
|
TDS
|
|
|
|
|
Suspended
Particles
|
|
|
|
|
COD
|
|
|
|
|
Chloride
ion
|
|
|
|
|
Sodium
ion
|
|
|
|
|
Pottasium
ion
|
|
|
|
|
Ferric
ion
|
|
|
|
|
Ferrous
ion
|
|
|
|
|
Nitrate
ion
|
|
|
|
|
Nitrite
ion
|
|
|
|
|
Phosphate
ion
|
|
|
|
|
Manganese
ion
|
|
|
|
|
Chromate
ion
|
|
|
Disscussion:
The data
we had obtained from the analysis was compared with the standard values that
were given by WHO. According to WHO, there was no guidelines for DO, TDS,
Suspended particles and Iron. DO i.e.
the amount of dissolved oxygen in the water is found to be very less than COD
i.e. Chemical oxygen demand in both river water and pump water. Total dissolved
solid (TDS) and Total suspended particles in the river is found to be greater
than the pump water. Chloride ions,
Sodium ions, nitrate ions and nitrite ions in both of the samples are
grater than the standard value. There is a slight change in the scenario with
Manganese. The concentration of Manganese in the both of the sample water is
grater than the standard. In sample
containing the river water, values for chromate ion is nearly equal to the
value given by WHO that means the concentration of chromium in it is optimum
GANTT CHART
|
Works
|
Weeks with 6
hours
|
||||||||
|
Proposal
|
|
|
|
|
|
|
|
|
|
|
Sample Collection
|
|
|
|
|
|
|
|
|
|
|
Lab analysis
|
|
|
|
|
|
|
|
|
|
|
Report
|
|
|
|
|
|
|
|
|
|
|
Presentation
|
|
|
|
|
|
|
|
|
|
Weeks-
CONCLUSION:
Various parameters of the
water quality was tested for the samples taken from the river as well as the
tube well nearby. The testing showed that parameters like Dissolved oxygen,
Total Dissolved Solids, Suspended Particles, Chemical Oxygen Demand, Ferric
ion, Nitrate ion, Chromate ion, and Manganese ion didn’t had any significant
leaching while parameters like Sodium, Potassium, Chloride ion, Ferrous ion, Nitrite
ion, and phosphate was found to be leached very significantly.
The concentrations of
many parameters were found to exceed such limits. Those elements should be
prevented from leaching .The concentration of these elements shouldn’t be
increased in the river system by wasting dumps and throwing garbage into the
river.
Reference
water sample test
