development and sensitivity analysis of water quality index for evaluation of
TRANSCRIPT
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DEVELOPMENT AND SENSITIVITY ANALYSIS OF WATER QUALITY
INDEX FOR EVALUATION OF SURFACE WATER FOR DRINKING
PURPOSE
R. S. Sapkal1, Dr. S. S. Valunjkar
2
1Research Scholar, Department of Civil Engineering, Government College of Engineering,
Aurangabad, Maharashtra, India2Professor in Civil Engineering, Government College of Engineering, Karad, Sistt: Satara,
Maharashtra, India
ABSTRACT
Water pollution not only affects water quality but also threats human health, economic
developments & social prosperity Internationally there are number of attempts made to produce a
method that meaningfully integrates the data sets and converts them into simple information called as
Water Quality Index (WQI) Water quality indices are used as comprehensive evaluation instrumentto assess the river water quality. Water quality index makes expert knowledge available to expert
users and public in general. The indices are formulated based either on studies conducted by the
indices developers or are formulated based on the Delphi technique which takes into account the
opinion of experts or mathematical formulation or by using fuzzy logic. In this study the water
quality index is developed by assigning relative weights to each parameter ranging from 1 to 6 based
on the adverse effect of the water quality parameter on human health, its concentration with respect
to other water quality parameters and method of treatment required. It includes twenty five water
quality parameters such as Color water temperature, pH, Electrical Conductivity (EC), Turbidity,
Suspended Solids (SS), Total Dissolved Solids (TDS), Total Hardness (TH), Total Alkalinity (TA),
Dissolved Oxygen (DO), Biochemical oxygen demand (BOD), Chemical oxygen demand (COD),
Sulfates (SO4- -
),, Chlorides, Total Phosphates ( TP-), Calcium (Ca
++),
Magnesium (Mg++
), Fluorides
Ammonium- Nitrogen (NH3-N), Nitrate-Nitrogen (NO3-N), Nitrite-Nitrogen (NO2-N) Total coliform(TC), Fecal coliform (FC), Sodium (Na+) and Boron(B) Water quality is categorized into five levels
based on the values of water quality index as Excellent (WQI = 95 to 100), Good (WQI = 80 to 94),
Fair (WQI = 65 to 79), Marginal (WQI = 45 to 64) and Poor (WQI = 0 to 44). The sensitivity
analysis shows that this WQI is not influenced by any one or few parameters but it is a combined
effect of all the parameters. It is applied to Purna (Tapi) river basin of Maharashtra (India).
Key words: Method of aggregation, Purna River, Water Quality Index, water quality parameters
INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND
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ISSN 0976 6308 (Print)
ISSN 0976 6316(Online)
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1. INTRODUCTION
Nowadays environmental protection and water quality management has become an important
issue in public policies throughout the world Many countries have introduced a scheme of river
water quality monitoring and assessment of surface water in terms of their physical, chemical,
biological and nutrient constituents and overall aesthetic condition [1]. There are number of methodsto analyze water quality data depending on informational goals, the type of samples and size of
sampling area. The water quality is difficult to evaluate from a large number of samples each
containing concentrations for many parameters. One of the most effective ways to communicate
information on environmental trends and river water quality in particular is with indices Water
quality index is a means to summarize large amount of water quality data in to simple language (i.e.
good, average or poor quality) for responding to management and the general public in consistent
manner. It tells us whether the overall quality of water body possesses a potential to various uses of
water such as irrigation, recreation or drinking water purpose.
Water Quality Index (WQI.) a great deal was given to the development of index methods by
Brown R. M., McClelland N. R., Deininger R. A. and Tozer R. Z. [2] of United States proposed a
WQI known as National Sanitation Foundation Water Quality Index (NSF WQI.) It was designed to
evaluate general water quality irrespective of water use. It included nine water quality parameters -
Dissolved Oxygen (DO), Fecal Coli form (FC), pH, Biochemical oxygen demand (BOD), Nitrate -
Nitrite, Phosphorous, turbidity, temperature and total solids Initially water quality and score ranges
were subdivided into seven classes as follows. Excellent (90-100), Good (80-89), slightly good (70-
79), Average (50-59), slightly bad (40-49), bad (20-39) and very bad (below 19). Initially it was
based on arithmetic mean of weighted sub-index of each variable. So it was not significantly
sensitive to change in the values of variables. Then it was modified by taking the geometric mean
After modification the water quality and score ranges were subdivided into five classes i.e.,
Excellent- A (91-100), Good-B (71-90), Medium-C (51-70), Bad-D (26-50) and Very bad E (0-25)
It serves as the basis of other several water quality indices. Curtis G Cude [3], Oregon Department of
Environmental Quality [4] had developed Oregon water quality index (OWQI) in 1970 and modified
it in 1990. The OWQI also serves as the bench mark indicator of stream water quality for the OregonProgress Board. Bindu M. Lohani and G. Todino [5] used factor analysis (FA) to develop water
quality index for Chao Phraya river in Thailand. Bhargave D. S., (1985) [6] suggested grouping of
water quality parameters for drinking purpose and evaluated a water quality index for drinking water
supplies.
L Gabriel T., de Azevedo, Timothy K. Gates, Darrell G. Fontane, John W. Labadie and
Ruben L. Porto [7] had combined the surface water quantity and quality objectives to develop water
quality routing and water allocation model for Piracizaba river in Brazil. Six management
alternatives combining various reservoir policies with differing levels of treatment were suggested.
Canadian Council of Ministers for Environment (CCME) [8] developed a water quality index called
as Canadian Council of Ministers for Environment Water quality Index (CCME WQI) it compared
observations to a bench mark where bench mark may be a water quality standard or site specific
variable concentration. It included ten water quality variables including 2, 4- D and lindane, itquantifies for one station over a predetermined period of time (typical one year) the number of
parameters that exceeded the bench mark the magnitude of exceedance and the number of records
exceeded the bench mark. The index is flexible in terms of the bench marks that are used for
calculations Sites at which water quality measurement never or rarely exceed the benchmark have
high CCME WQI (near 100) where as sites that routinely have measurements that exceed
benchmarks have low CCME WQI (near 0).The water quality levels suggested are Excellent (95 -
100), Good (80-94), Fair (65-79), Marginal (45-64) and Poor (below 45) Shiow - Mey Liou, Shang -
Lien Lo and Shan - Hsien Wang (2004) [9] proposed a overall index for water quality in Taiwan and
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its application in Keya river. Ahmaid Said et.al [10] defined a new water quality index for Big Lost
river water shed in Idhao. to assess water quality for general use Chinmoy Sarkar and S. A. Abbasi,
[11] have developed a software called QUALIDEX to determine various WQI William Ocampo-
Duque et.al [12], have developed WQI by using fuzzy inference system.
S. S. Asadi, Padmaja Vuppala and M. Anji Reddy [13] assessed the ground water quality in
Municipal corporation of Hyderabad (India) by using water quality index related to land use. Theyhave used remote sensing and GIS techniques for evaluation of groundwater quality for development
of water quality index Fuzhan Nasiri et al. [14], proposed fuzzy multiple attribute decision support
system to compute water quality index and to provide alternative plans based on improvement in
water quality index. Prabhata K. Swamee and Aditya Tyagi [15] used alternative method to describe
water quality using aggregate index consisting of sub-indices for water quality variables. L. K.
Diadovski and M. P. Atanassova [16] had developed an integral index of the tropic pollution level
for Mesta river of Bulgeria. The water quality parameter considered were BOD, COD, total nitrogen,
total phosphorus DO, metals like cadmium chromium copper, Zinc and lead, detergent phenol and
coli form. K values for each parameter was determined and the integral index was formulated.
Mohsen [17] had developed WQI to describe water contributed by mining activities in Malaysia. The
water quality index was calculated by considering nine water quality parameters. Yilmaz Icaga
(2007) [18] suggested a WQI model using fuzzy logic and applied it to assess the water quality of
Eber Lake (Turkey). He has tried to remove the ambiguities due to concentration level of the
parameter very close to the permissible limits. Prakash Raj Kannad, Seockheon Lee Young Soo Lee,
Sushil Raj Kannel, Siddhi Pratap Khan [19] have investigated: WQI considering 18 water quality
parameters, WQImin &WQIm (mean water quality index) and WQIDO (considering a single parameter
DO) Hulya Boyacioglu [20] ,[21] developed universal WQI (UWQI) based on European
Classification Scheme
Andre Lermontov et al [22], used fuzzy logic to develop water quality index called as fuzzy
water quality index (FWQI) for Pardo river, Brazil. Chaiwar Prakirake et al.[23], developed water
quality index (WQI) applying Delphi technique Dinesh Kumar and Babu J. Allappat [24] studied
National Sanitation foundation water quality index (NSF-WQI) and brought out the short comings in
the formation of NSF WQI and suggested the possible improvement. M. K. Chaturvedi and J. K.Bassin (2009) [25] have assessed the water quality index for water treatment plant and bore well in
Delhi area using NSFWQI to classify water quality as excellent, good, medium, bad and very bad.
Abdul Hameed Jawad Alobaidy [26] developed WQI using cluster analysis and by considering
thirteen water quality parameters Mohamad Ali Fulazzaky et. al [27], assessed the water quality of
Selongor river from nine stations along the main stream using WQI. Avnish Chauhan and Suman
Singh [28] developed WQI by considering eight water quality variables (Turbidity, DO, BOD, COD
,free CO2, Total solids( TS),Total Suspended Solids(TSS) & TDS) & applied it to evaluate Ganga
water for drinking purpose & concluded that Ganga Action Plan launched by Government of India
has failed to reduce the pollution level in Ganga river. Abdul Hameed M. Jawed Alobaidy, Haider S.
Abid and Bahram K. Maulood [29] developed water quality index considering ten water quality
parameters. This WQI was applied to assess the water quality of Docan Lake, Iraq.
1.1. Aggregation FunctionsIt is the most important step in calculating WQI. In order to minimize ambiguity and
eclipsing, it is necessary to identify an appropriate function of calculating and aggregated score. The
following functions are normally used. Table 1 shows various aggregation functions
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Table 1: Various aggregation functions
Aggregation
function
Formula Remarks
Weighted sum
index
This method of aggregation is free
from ambiguity but suffers from
eclipsing.Multiplicative
product index or
weighted geometric
function
WQI Qi
In this aggregation function, an
index is zero if any one sub index
is zero. This characteristic
eliminates the eclipsing as well as
ambiguity problem
Weighted Solway
function 1100 Un-weighted
Solway function 1100 1
Un-weighted
geometric function WQI= }1/nRoot mean square
function 0.5 1/
Un-weighted
harmonicsquare mean function
Maximum Operator
index I1, I2, I3, In This is ideally suited to
applications in which an index
must report if at least one
recommended unit is violated
Minimum Operator
index I1, I2, I3, In This aggregation method is free
from eclipsing as well as
ambiguity
Where, = sub-index forth
variable
= relative weight forth
variable
2.0 MATERIALS AND METHODS
2.1 Development of Water Quality IndexThe indices are formulated based either on studies conducted by the indices developers or are
formulated based on the Delphi technique which takes into account the opinion of experts or
mathematical formulation or by using fuzzy logic. In this study WQI is developed as follows
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2.1.1 Selection of parameters
Water quality parameters were selected based on the criteria- Parameters considered by
previous researchers, parameters for which data is available and will be available over wide range of
time, parameters producing adverse effect on human health It includes twenty five water quality
parameters such as Color water temperature, pH, Electrical Conductivity (EC), Turbidity, Suspended
Solids (SS), Total Dissolved Solids (TDS), Total Hardness (TH), Total Alkalinity (TA), DissolvedOxygen (DO), Biochemical oxygen demand (BOD), Chemical oxygen demand (COD), Sulfates
(SO4- -
),, Chlorides, Total Phosphates ( TP-), Calcium (Ca
++),
Magnesium (Mg++
), Fluorides
Ammonium- Nitrogen (NH3-N), Nitrate-Nitrogen (NO3-N), Nitrite-Nitrogen (NO2-N) Total coliform
(TC), Fecal coliform (FC), Sodium (Na+) and Boron(B)
2.1.2 Assigning weightEach selected parameter was assigned a weight (WA) based on the criteria shown in Table 2
and Table 3. The parameter which produces adverse effect on human health, has more concentration
relative to other parameters and requiring advance or special treatment method for its removal, is
assigned less weight so that it should lower the WQI. The parameters which does not have any
adverse effect on human health, has less concentration relative to other parameters and requires
conventional method for its removal is assigned a higher weight so that it should increase the WQI.
Excursion for parameter is determined based on the concentration (test value) of parameter and the
guideline value. It is determined as follows.
Table 2: Importance of water quality parameters
Parameter Unit
WHO [30],
BIS [31],
and CPCB
[32]
permissible
limits
Effect on human health
beyond permissible
limit/ guideline value
Method for
removal
Remarks
Color TCU 15 No direct health effectAesthetically unpleasant
[31]
Conventional* treatment
Color is due tonatural organic matter
and colloidal matterfrom suspended
solids, iron,manganese, Here truecolor is considered.
TemperatureO
C 18 - 22 No health effect Only
aesthetic effect
-
Higher temperature
suggests that the
water has feweramount of insoluble
pollutants [33]Temperature is
known to influencepH, alkalinity and
DO [34] Rate ofbiological reaction
and production ofbacteria increases [1]
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pH - 6.5 8.5 No sufficient evidences
for adverse effect are
available Only aestheticeffect
Conventional
treatment
pH > 8.5, water is
bitter in taste. [35]
Ammonia changes tomore toxic state of
un-ionized ammonia
at pH> 7. Colorintensity increases
with increase in pH[36]
Electrical
Conductivity S/cm 750
No health effect It
greatly affects the taste[26]
Conventional
treatment
Depends on amount
of total dissolvedsolids in water. It
represents he salinity
It is function oftemperature and
number of dissolved
ions in water. [10, 33]
Water reach inbicarbonate, calciumand magnesium has
low conductivity.Water with high
conductivity hasmore concentration of
sodium and chlorides.[7]
Turbidity NTU 5 Aesthetic ally unpleasant
[31]
Conventional
treatment
Indicates more
amount of suspendedmatter and indicates
possibility of harmfulmatter [10]
SuspendedSolids
mg/l 25 No direct adverse effecton human health Only
aesthetic effect
Conventionaltreatment
It contributes toturbidity of water. It
increases water
temperature byabsorbing heat from
sunlight leading to
depletion of DO [37]
TotalDissolved
Solids
mg/l 500Only aesthetic effect Conventional
treatmentAffects electricalconductivity
Total
hardness
mg/l 300 Only aesthetic effect Lime
softening
Reduces toxicity of
cadmium, lead, nickel
and zinc [38]
TotalAlkalinity
mg/l 200 Only aesthetic effect Conventionaltreatment
If alkalinity is toohigh water becomesturbid.
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Biochemical
oxygen
demand
mg/l
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Total
phosphates
mg/l 0.4 Only aesthetic effect Precipitation
with Fe (III),
Aluminum(III)
Excess phosphorus
causes algal growth
decreasing the DOlevel & rises water
temperature [10]
Ammonium-nitrogen mg/l 0.5
Only aesthetic effect Ion exchange It depends ontemperature, pH and
total dissolved solids[3]
Nitrate-
nitrogen
mg/l 10 High concentration
causes
methaemoglobinemia orblue baby disease in
infants
Ion exchange --
Nitrite-
Nitrogen
mg/l 1 Presence of nitrite in
water is dangerousNitrite reacts with nitro-sotable compounds in
the body to form N-nitro -so compounds
which are carcinogenic
[36]
Conventional
treatment(Chlorination)
--
Parameter Unit WHO
guideline
value / IS /
CPCB
permissible
limits
Effect on human health
beyond permissible
limit/ guideline value
Method for
removal
Remarks
Total
coliform
MPN/
100ml 0
Causes gastroentitis,
urinary tract infection,diarrhea , typhoid fever,
bacillary dysentery[36]
Conventional
treatment
It is influenced by
temperature
Faecalcoliform
MPN/100ml 0
Causes gastroentitis,urinary tract infection,
diarrhea [36]
Conventionaltreatment
It is influenced bytemperature
Sodium mg/l 200 Impart taste to water Ion exchange --
Boron mg/l 0.5 It develops metal
toxicity It is toxic toreproductive tract
Ion exchange
and ReverseOsmosis
--
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Table 3: Criteria for assigning weights to water quality parameters
Sr.
No.
Criteria Description Weight
(WA)
Minimum
weight
Maximum
weight
1 Effect on humanhealth
Aesthetic effect only 21 2Aesthetic effect and adverse
effect on health
1
Only adverse effect on health 1
2 Parameter
concentration
related to
concentration of
other parameters
Excursion of parameter
concentration less than average
excursion
2
1 2
Excursion of parameter
concentration more than
average excursion
1
3 Treatment method
(Method for
removal)
Conventional treatment process 2
1 2Advance / Special treatment
process
1
Minimum / Maximum weight 3 6
Test value exceeds the guideline value excursion 1 (1)Test value below the guideline value excursion
1 (2)
Calculation of relative weight
A relative weight R for each parameter is calculated by using equation (3) [i.e. dividingassigned weight of parameter (WA) by sum of assigned weights of all parameters A ].
, and R 1 (3)2.1.3 Construction of Sub-Index Equations for Individual Selected Parameter
To assign the sub-index values, the water quality parameters guideline values (permissible
limits) of World Health Organization [30], Bureau of Indian Standards (BIS) [31] and Central
Pollution Control Board (CPCB) [32] are used The water quality sub-index equations are formulatedaccording to the water quality classification used in this study The For a parameter which requires
only conventional method of treatment, the parameter concentration equal to guideline value is
considered at WQI value of 80 whereas for a parameter which requires advance or special method of
treatment, parameter concentration equal to guideline value is considered at a WQI value of 60 This
is done so that WQI should represent correct water quality The sub-index equations for various
parameters are shown in Table 4
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Table 4: Sub-index equationsWater
qualityparameter
Sub-index equation Water
qualityparameter
Sub-index equation
Color x 5,
15 < x 300,
x 15x > 300,
y=100
y = -0.254x+81
y = -1.872x+106.1y = 0
Chlorides x 78,
75 < x 5000
x > 5000,
y = 100
y = -23.3ln(x)+198.9
y = 100
Temperature x 3,x 18,
18 > x 22,22 < x 37,x > 37,
y = 0y = 6.441x-12.37
y = 100y = -6.228x+233.7
y = 0
Calcium x 10,10 < x 425,
x > 425
y = 100y = 0.0001x
2-
0.274x+98.73y = 0
pH x 2,
2 < x < 77 x 13,
x >13,
y = 0
y = 2.695x2-5.95x+2
y = 2.914x2-78.66x+528
y = 0
Magnesium x 5,
5 < x 180,x > 180,
y = 100
y = 0.001x2-0.716x+100
y = 0
Electrical
conductivity
x 275,
275 2.2,
y = 0
y = 65.8x5+412.2x
4-
888.8x3+685.8x
2-
47.27x+3.415
y = 100y = 0
Turbidity x 2,2 < x 200,
x> 200,
y = 100y = -21.4ln(x)+115
y = 0
Totalphosphates
x 0.1,0.1 < x 7.5,
x > 7.5,
y = 100y = -22.4ln(x)+47.88
y = 0
Suspended
solids
x 5,
5 < x 190,
x > 190,
y = 100
y = 0.001x2-0.542x+102
y = 0
NH3 - N
x 0.03,
0.3 < x 40,
x> 40,
y = 100
y = -13.8ln(x)+51.78
y = 0
Total
dissolved
solids
x 180,
180 28000
y = 0
y = -18.5ln(x)+196.4
y = 0
NO3 N
x 2,
2 < x 14.5,
15 < x 50,x > 40,
y = 100
y = -4.356x+102
y = -30.6ln(x)+120.3y = 0
Total
hardness
x 50,
50< x 2500,
x > 2500,
y = 100
y = 1E-05x2-0.066x+109.8
y = 0
NO2 - N
x 0.04,
0.4 < x 28,
x > 28,
y = 100
y = -15.3ln(x)+52.11
Total
alkalinity
x 20,
20 < x 780,
7503000,
y = 100
y = -0.105x+102
y = -0.008x+26
y = 0
Total
Coliform
x 0,
0< x 50,
50< x 400,
400 < x 70000x>70000,
y = 100
y = -0.403x+100
y = -0.028x+81.2
y = -0.001x+70.77y = 0
Dissolvedoxygen
x < 1,1 x 13,
y = 0y = -0.14x
3+1.468x
2+
9.519x-2.088y = 100
y = -0.14x3+1.468x
2+
9.519x-2.088
y = 0
FecalColiform
x 0,0< x 20,
20 < x 200,200 < x 34000,
x> 350000,
y = 100y = -x+100
y=-0.055+81.11y = -0.002x+69.76
y= 0
BOD x 1,
1 < x 90,
x > 90,
y = 100
y = -23.3ln(x)+105.7
y = 0
Sodium
x 65,
65 < x 2000,
x > 2000,
y = 100
y = -27.8ln(x)+212.1
y = 0
COD x 9,9 < x 450,
x > 450,
y = 100y = -25.3ln(x)+155.5
y = 0
Boronx 0.075,0.075 < x 10,
x>10,
y = 100y = -19.9ln(x)+47.22
y = 0
Sulfates x 40,
40 < x 2000,
x > 2000,
y = 100
y = -23.4ln(x)+188.8
y = 0
Where, x = Concentration of parameter and y = Water quality
Sub-index
2.1.4 Overall WQI
The multiplicative product method of aggregation is used to overcome problems of eclipsing
and ambiguity Overall water quality index is determined by formula given in equation (4)
(4)
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2.1.5Water Quality CategorizationThe water quality is classified into five categories Table 5 shows the water quality index
(WQI) ranges and the classification of water
Table 5: Ranges of Water Quality Index and water quality category (CCME, 2001)
Water qualitycategory
Water QualityIndex Values
Water quality description
Excellent 95 - 100 Water quality is protected with a virtual absence of threat orimpairment. All measurements are within objectives virtually of all
the time
Good 80 - 94 Water quality is protected with minor degree of threat orimpairment; conditions rarely depart from desirable levels
Fair 65 - 79 Water quality is protected but occasionally threatened or impaired;
conditions sometimes depart from desirable levels
Marginal 45 - 64 Water quality is frequently threatened or impaired; conditions often
depart from desirable levels
Poor 0 - 44 Water quality is almost always threatened or impaired; conditions
usually depart from desirable levelsSource: Canadian water quality guidelines for protection of aquatic life : CCME water quality
index, Users manual. CCME 2001
3.0 STUDY AREA
The study area includes Purna (Tapi) river basin of Maharashtra, INDIA Purna river originates at It
flows southwards through Amravati district, then westwards through Akola and Buldana districts to
discharge itself into Tapi river near Changdeo in Jalgaon district Total length of Purna river is 334 m
The river is perennial and has many tributaries The climate of this area is dry and hot except for
monsoon (June-September) The basin area is about 7800 Km2
out of which central 3000 Km2
is
known as saline track Yearly rainfall is 700-800 mm Six stations were identified for development of
WQI Fig 1 shows Purna (Tapi) river basin and location of identified stations
Fig 1: Purna (Tapi) river basin
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4.0 RESULTS AND DISCUSSION
Table 6 shows typical water quality characteristics of Purna (Tapi) river basin WQI so
developed is applied to selected stations of Purna (Tapi) river basin Temperature, total coliform,
Fecal coliform, Suspended solids and turbidity exceeded the guideline value deteriorating the water
quality and lowering WQI Fig shows parameters that are exceeded (as percentage of totalexceedance) over the guideline value More than 50% exceedance is due to temperature, total
coliform and Fecal coliform together where as parameters like Sulfates, Chlorides, Calcium,
Magnesium, Total phosphates, Nitrate Nitrogen and sodium are not exceeded the guideline value at
all The water quality of these stations is categorized as good.
Table 6: Water quality characteristics of Purna (Tapi) river basin
Parameter Mean SD Parameter Mean SD Parameter Mean SD
Color 6 0.167 DO 6.290.669 TP 0.0660.079
Temperature 28.7 8.440 BOD 2.730.924 NH3-N 0.2020.0411.041pH 8.340.213 COD 10.050.637 NO3-N 0.6880.597
EC 438162 Sulfates 12.446.152 NO2-N 0.070.200
Turbidity 3270 Chlorides 51.7841.903 Total Coli 9199
SS 3348 Calcium 26.508.091 Faecal Coli 3748
TDS 289120 Magnesium 22.259.886 Sodium 87.2427.552
TH 158 Fluorides 0.5340,267 Boron 0.1510.152
TA 16451
Fig 2 shows variation in WQI in winter and summer for these stations Due to increased
concentration of turbidity, suspended solids, total coliform and fecal coliform in winter lower the
WQI whereas the water is very clean with concentration of turbidity and suspended solids improved
the WQI in summer Fig 3 shows variation in WQI for these stations during 2005- 2008.
Table 7 show correlation coefficient between WQI and concentration of parameters All parameters
shown negative correlation with negative correlation with WQI except for color, pH, temperature,
dissolved oxygen, sulfates and fluorides Positive correlation between WQI and dissolve oxygen
indicates that as dissolved oxygen increases WQI also increases pH values are mostly less than 8.5
As pH concentration approaches to guideline value of 6.5-8.5, WQI increases Guideline value range
for temperature is 18 OC22 OC as water temperature approaches to this range WQI increases Forcolor and sulfates the concentrations are well within guideline value, so the decrease in WQI is not
due to these parameters but it is due to the combined effect of all other parameters. While deciding
the water quality sub-index equation, lower guideline value of 0.6 mg/l is decided to avoid dental
carries Fluoride concentration are well within guideline value and as these concentrations approaches
to 0.6 mg/l, it lowers the WQI
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Fig 2: Variation in WQI in winter and summer Fig 3: Variation in WQI during 2005-2008
Table 7: Correlation coefficient between WQI and Concentration of parameters
Parameter r Parameter r Parameter r
Color 0.435 DO 0.880 TP -0.901
Temperature 0.486 BOD -0.898 NH3-N -0.597
pH 0.411 COD -0.838 NO3-N -0.255
EC -0.610 Sulfates 0.172 NO2-N -0.250
Turbidity -0.689 Chlorides -0.795 Total Coli -0.955
SS -0.960 Calcium -0.303 Fecal Coli -0.831
TDS -0.7 Magnesium -0.449 Sodium -0.804
TH -0.777 Fluorides 0.346 Boron -0.064
TA -0.496
r =Correlation coefficient
4.1 Sensitivity Analysis
WQI was also determined by removing each parameter at a time Fig 6 shows WQI after
removal of the said parameter. It is observed that WQI is not varied much due to removal of an
individual parameter. Table 8 shows correlation coefficient between WOI and WQI after a particular
parameter is removed. All parameters have shown positive correlation with WQI after its removal.
No parameters have shown negative correlation with WQI after its removal. It shows that WQI is not
influenced only by one or few parameters but it is the combined effect of all the parameters. It is
varied much due to turbidity, temperature and fluorides. Turbidity is exceeded much the guideline
value during winter particularly in monsoon which contributed to lower the overall WQIAfter removal of turbidity, WQI is increased. Climate of Purna (Tapi) river basin being dry and hot
throughout the year, water temperature exceeded the guideline value to lower WQI. After removal of
temperature WQI is increased Fluoride concentration is well within guideline value. The water
quality sub-index equation is such that it lowers WQI if concentration of fluoride is less than 0.6
mg/l to avoid dental carries, after its removal WQI is increased. Though percentage exceedance of
concentration is more, but as it is within certain limit which have not contributed much to lower WQI
after removal of these parameter.
78
8082
84
86
88
90
S1 S2 S3 S4 S5 S6
WQI Winter
WQI Summer
WQI
70
75
80
85
90
S1 S2 S3 S4 S5 S6
2005
2006
2007
2008
W
QI
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Table 8: Correlation coefficient between WQI and WQI after removal of particular parameters
Parameter r Parameter r Parameter r
Color 0.840 DO 0.872 TP 0.830
Temperature 0.913 BOD 0.901 NH3-N 0.895
pH 0.843 COD 0.827 NO3-N 0.843
EC 0.748 Sulfates 0.809 NO2-N 0.880
Turbidity 0.896 Chlorides 0.840 Total Coli 0.830
SS 0.872 Calcium 0.830 Fecal Coli 0.830
TDS 0.757 Magnesium 0.895 Sodium 0.840
TH 0.783 Fluorides 0.651 Boron 0.871
TA 0.895
r =Correlation coefficient
5.0 CONCLUSION
In this study, WQI based mathematical formulation by assigning weights to various physio-
chemical water quality parameters are proposed based on its adverse effect on human health, itsconcentration relative to the concentration of other parameters and method of treatment required for
it. The new WQI is believed to assist the decision makers in reporting the state of water quality for
drinking purpose. The applicability & usefulness of proposed methodology is revealed by a case
study. The sensitivity analysis shows that this WQI is not influenced by any one or few parameters
but it is a combined effect of all the parameters this WQI could be used to evaluate the water quality
of any water body to judge its suitability for drinking purpose. This WQI forces the researchers to
assign same weight to the same parameter, moreover this WQI is free from ambiguity and eclipsing.
REFERENCES
[1] A. A. Najufpoor, Z. Vojodur, M. H. Dehgani, H. Acidadi, (2007), Quality assessment of
Kashif river in North-east of Iran in 1996-2005 Journal of Applied Sciences 7(2), 2007, pp253-257.
[2] Brown, R. M: McClell and, N. I, Deininger, R. A and Ronald, G. T A water quality index
Do we dare? Water Sewage Works 11, 1970, pp 335- 343
[3] Curtis G. Cude, Oregon water quality index: A tool for evaluating water quality
management effectiveness Journal of American water works association Vol. 37, No. 1,
2001, pp 125-137.
[4] Curtis G. Cude, Reply to discussion on Oregon water quality index: A tool for evaluating
water quality management by, David G. Smith, Robert J. Davies- Colley and John W.
Nagels, Journal of the American management by, David G. Smith, Robert J. Davies- Colley
and John W. Nagels, Journal of the American Water Resources Association, Vol. 38, No. 1,
Feb, 2002, 315-318
[5] Bindu N. Lodhani (1985), Water quality index for Chao Phraya River Journal ofEnvironmental Engineering Vol. 110, No. 6, 1984 pp 1663.
[6] Bhagava D. S., Expression for drinking water supply standards Journal of
Environmental Engineering Vol 3 No. 3, 1985 pp 304-316.
[7] L .Gabriel T, de Azevedo, Timothy K. Gates, Integration of water quality and quantity in
strategic river basis planning Journal of water resources planning & management Vol. 126,
No. 2, 2000, pp 85-97.
[8] CCME (2001), Canadian water quality guidelines for protection of aquatic life: CCME
water quality index, Users manual. CCME 2001
-
7/27/2019 Development and Sensitivity Analysis of Water Quality Index for Evaluation Of
15/16
International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 6308
(Print), ISSN 0976 6316(Online) Volume 4, Issue 4, July-August (2013), IAEME
133
[9] Shiow Mey Lion, Shang-Lien Lo and Shan-Hsien Wang, A generalized water quality index
for Taiwan Environmental Monitoring Assessment,96 : 35-52, 2004
[10] Ahmaid Said, David Stevens, Gerald Sehlke, (2004), An innovative index for evaluating
water quality in streams, Environmental Assessment, Vol. 34 No. 3, 2004, pp 406-414
[11] Chinmoy Sarkar and S. A. Abbasi, QUALIDEX A new software for generating water
quality indices, Environmental monitoring Assessment, 119, 2006, 201-231[12] William Andre Ocampo Duque, On the development of decision making systems based on
fuzzy models to assess water quality in rivers, Ph. D. Thesis, Universitat Rovira I Virgili,
Tarragona, 2008
[13] S. S. Aadi, Padmaja Vapulla, M Anji Reddy, Remote sensing and GIS technique for
evaluation of ground water quality In Municipal Corporation Hyderabad (Zone-V) India
International Journal of Environmental Research and Pollution Health, 4(1), 2007 pp 45-52
[14] Furhan Iqbal, M. Ali, Abdus Salam,B. A. Khan, S. Ahmad, M. Qamar and Kashif
Umer,Seasonal variation of physio-chemical characteristics of River Soan water at Dhoak
Pathan Bridge (Chakwal), Pakistan, International Journal of Agricultural and Biology, 6 (1),
2004, 89-92
[15] Prabhata Swamee and Aditya Tyagi, Improved method for Aggregation of water quality
sub- indices Journal of Environmental Engineering Vol. 13 No. 2, 2007 pp 220-225
[16] L. K. Diadovski and M. P. Atanasaova (2007), Water quality management based on the
integral approach Water Quality Management, Chem. Biochem. Engg. 21 (2) 2007 pp 189-
194.
[17] Mohsen Nasirin, 2007 A new water quality index for environmental contamination
controlled by mineral processing: A case study of among (Tin Talling) processing activity
Journal of Applied Science 7(20)2977-2987, 2007
[18] Yilmaz Icaga, Fuzzy evaluation of water quality classification, Ecological Indicators, 7,
2007, 710-718
[19] Prakash Raj Kannad, Seockheon Lee Young Soo Lee, Sushil Raj Kannel, Siddhi Pratap
Khan,Application of water quality indices and Dissolved oxygen as indicators for river
water classification and urban impact assessment, Environmental monitoring Assessment,132,2007, 93-110
[20] Hulya Boyacioglu, Development of water quality index based on a European classification
scheme, Water SA, Vol. 33, No. 1. Jan. 2007, pp 101-106
[21] Hulya Boyacioglu, Utilization of water quality index method as a classification tool,
Environmental monitoring Assessment, 167 (2010), 115-124
[22] Andre Lormontov, Lidia Yokoyama, Mihail Lermontov and Maria Augusta Soares
Machado, River quality analysis using fuzzy water quality index: Riberia do Iguape river
watershed, Brazil, Ecological indicators, 9, 2009,1188-1197
[23] Chaiwat Prakirake, Pawinee Chaipraset and Sudarut Tripetchkul, (2009) Development of
Specific water quality index for water supply in Thailand Songklanakarin J. Science
Technology 31, (1) 2009 pp 91-104.
[24] Dinesh Kumar, Babu J. Alappat, N.S.F. Water quality index : Does it represents the Expertopinion?Practice Periodical of Hazardous, Toxic and Radioactive Waste Management Vol.
13 No. 1, 2009 pp 75-79
[25] M. K. Chaturvedi and K. Basin, Assessing water quality index of water treatment plant and
bore wells in Delhi, India, Environment monitoring Assessment, 163 ,2010, 449-453
[26] Abdul Hameed Jawad Alobaidy, Evaluating raw and treated water quality of Tigris river
within Baghdad by Index analysis, 2010, file;//localhost/E/wqi121109.mht
-
7/27/2019 Development and Sensitivity Analysis of Water Quality Index for Evaluation Of
16/16
International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 6308
(Print), ISSN 0976 6316(Online) Volume 4, Issue 4, July-August (2013), IAEME
134
[27] Mohammad Ali Fulazzaky, Teng Wee Seong and Mohamad Idrus Mohamad Masirin, (2010),
Assessment of water quality status for the Selongor river in Malaysia, Water, Air, Soilpollution, 205, 2010 63-77
[28] Avnish Chauhan and Suman Singh, Evaluation of Ganga water for drinking purpose by\waterquality index at Rishikesh, Uttarakhand, India, Report and Opinion, 2 (9), 2010, 53-61
[29] Abdul Hameed Jawad Alobaidy, Haider S. Abid and Bahram K. Maulood, Application of waterquality index for assessment of Dokan Lake ecosystem , Kurdistan region, Iraq, Journal ofWater Resources and Protection, 2, 2010, 792-798
[30] World Health Organization, World Health Organization guidelines for drinking water qualityThird Edition, Incorporating first and second Addenda, Volume I, Geneva, 2008
[31] Bureau of Indian Standards, Indian Standard specifications for drinking water, IS 10500, 1991
with third amendment, July 2010[32] Central Pollution Control Board, (CPCB), Primary water quality criteria for designated best use
classes and general quality criteria for raw water for organized community water supplies
(Surface and Ground water), 2010, Government of India report[33] Khaiwal Ravindra, Ameena, Minakshi, Rani and Anubha Kaushik, (2003), Seasonal Variation in
physio-chemical characteristics of river Yamuna in Haryana and its ecological best- designated
use,Journal ofEnvironmental Monitoring, 5, 2003, 419-426.[34] K. V. Paliwal, (1972), Quality of water resources in India, Symposium on Water in mans life,
August 5-7, 1971, New Delhi
[35] Federal and Provincial Committee 0n Drinking Water (Canada), (2010), "Guidelines for
Canadian drinking water quality", Canada Health, 2010[36] Clair N. Sawyer, Perry L. McCarty and Gene F. Parkin, Chemistry for Environmental
Engineering and Science, McGraw Hill Publication
[37] Rashmi Sisodia and Chaturbhuj Moundiotiya (2006), Assessment of water quality index ofwetland Kalakho Lake, Rajasthan, India,Journal of Environmental Hydrology, Vol 14, No. 23,
2006, 1-1[38] Warren Viessman Jr. and Mark J. Hammer, Water Supply and Pollution Control, Prentice Hall
Water resources Division India and Northern Affairs Canada, Yellowknife NT, Canada, Peel
river basin water quality March 2002[39] Ene Indermitte, Astrid Saava and Enn Karro, (2009), Exposure to high Fluoride drinking water
and risk of dental Fluorosis in Estinia,International Journal of Environmental Research PublicHealth, 6, 2009, 710-721
[40] William Andre Ocampo Duque, (2008), On the development of decision making systems based
on fuzzy models to assess water quality in rivers, Ph. D. Thesis, Universitat Rovira I Virgili,
Tarragona, 2008
[41] Abdur Rahman, M. A. Zafor and Shantanu Kar, Analysis and Comparision of Surface Water
Quality Parameters in and Around Dhaka City, International Journal of Civil Engineering &
Technology (IJCIET), Volume 3, Issue 2, 2012, pp. 7 - 15, ISSN Print: 0976 6308,
ISSN Online: 0976 6316.[42] Rumman Mowla Chowdhury, Sardar Yafee Muntasir, Md. Niamul Naser and Sardar Rafee
Musabbir, Water Quality Analysis of Surface Water Bodies Along the Dhaka-Mawa-Bhanga
Road Based on Pre-Monsoon Water Quality Parameters for Aquaculture, International Journalof Civil Engineering & Technology (IJCIET), Volume 3, Issue 2, 2012, pp. 154 - 168,
ISSN Print: 0976 6308, ISSN Online: 0976 6316.[43] Neeraj D. Sharma and Dr. J. N. Patel, Experimental Study of Groundwater Quality Improvement
by Recharging with Rainwater, International Journal of Civil Engineering & Technology
(IJCIET), Volume 2, Issue 1, 2011, pp. 10 - 16, ISSN Print: 0976 6308, ISSN Online:
0976 6316.