INTERNATIONAL JOURNAL OF APPLIED ENGINEERING RESEARCH, DINDIGUL Volume 2, No 2, 2011

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1 RESEARCH ARTICLE ISSN Ground water chemistry: A case study of eastern part of Sikar city (Rajasthan), India Radhey Shyam, Kalwania.G.S Department of Chemistry, S.K. Government College Sikar332001(Rajasthan) India gskalwania@gmail.com ABSTRACT For major ions evolution and classification of ground water in eastern part of Sikar city, 21 ground water samples have collected and analyzed for different water quality parameters, such as ph, EC, TDS, TH, TA, DO, calcium, magnesium, sodium, potassium, carbonate, bicarbonate, chloride, nitrate, sulfate and fluoride with the help of standard methods recommended by American Public Health Association. The analysis indicated that EC, TDS, nitrate, chloride and fluoride content in some samples are at alarming state as compared to the WHO standards for drinking purposes, thereby suggesting the need for treatment and precautionary measures for use of the particular ground water. To classify the ground water ability for different purposes, various plots like U.S. salinity, Durov, Schoeller diagrams have been drawn and chemical indices like sodium absorption ratio, percent sodium, residual sodium carbonate, permeability index and chloro alkaline indices are calculated. Keywords: water chemistry, drinking, irrigation, statistical analysis, graphical plots 1. Introduction Water is the universal solvent and human survival depends on the use of uncontaminated and cleaned water. The physical, chemical and bacterial characteristics of ground water determine its usefulness for domestic, industrial, municipal and agricultural applications. The quality of water is more important compared to quantity in any water supply planning, especially for drinking purposes (CPHEEO, 1998 & Blais et al 1993). Water quality standards are the foundation of quality based control program and required for treatment process. These standards help to identify water quality problems caused by improperly treated waste water discharge from active or abandoned mixing sites, sediments and fertilizers. These standards also support efforts to achieve and maintain protective water quality conditions (CGWB, 2004 & Gajendra et al., 2008). The parameters of water quality i.e. ph, EC, TDS, TH, fluoride, chloride, nitrate, sulfate etc. should be in permissible limits (WHO, 1996 & Begum et al,2008). If these parameters cross the permissible limit of concentration, it may causes serious health hazards and such water is known as contaminated water. Sikar city ( latitude, N; and longitude, E) is one of the fastest growing area in Rajasthan( India ) due to proximity and well connectivity with world class pink city, Jaipur. This city is undergoing rapid industrialization and urbanization, which has led to immense pressure on ground water resources and it ultimately results the quality deterioration of ground water (Shyam and Kalwania, 2010&2011). The main objective of the present research work is to study the distribution of physicochemical parameters in ground water of Sikar city and provide reliable water quality data to 367

2 RESEARCH ARTICLE ISSN design economically effective methods for treatment of ground water and to make them potable with standard permissible limit of pollutants (Shyam and Kalwania, 2010&2011). 2 Materials and Methods The present research work is based on 21 ground water samples collected from tubewell in cleaned and screw capped polythene bottles. At the time of sampling, these bottles are thoroughly rinsed 23 times using the ground water to be sampled. These water samples are collected after pumping the water for 10 minutes (Shyam and Kalwania, 2010&2011). The water samples are analyzed for various physicochemical parameters using standards methods recommended by American Public Health Association (APHA, 1989). Six parameters i.e. EC (electrical conductivity), ph, TDS (total dissolved solids), DO (dissolved oxygen), salinity and turbidity are determined at the same day of sampling using Water Analyzer (Systronic 371). Total hardness (TH) and calcium hardness are determined by complexometric EDTA titration methods using eriochrome blackt (EBT) and murexide indicator respectively. Magnesium concentration is calculated from total hardness and calcium hardness. Total alkalinity (TA), carbonate and bicarbonate concentrations are estimated by titrametric methods using phenolphthalein and methylorange as indicator. Argentometric method with K 2 CrO 4 indicator is used to determine chloride concentration. With the help of double beam UVVIS Spectrophotometer (Systronic2201), fluoride, nitrate and sulfate concentration are determined using zirconyl SPADNS dye, brucine and turbidimetric methods respectively. Estimation of sodium, potassium and calcium are carried out by FlamePhotometric method (Systronic128, compressor126). 3. Results and Discussion The respective values of all water quality parameters are summarized in Table1a and 1b. All the results are compared with standards permissible limit recommended by the World Health Organization (WHO) and Indian Council of Medical Research (ICMR). The distribution pattern of major cations and anions in ground water of eastern part of Sikar city, based on the average values of these ions(mg L 1 ) are as Na + >> Ca +2 > Mg +2 >>K + and HCO 3 > Cl >> SO 4 2 > NO 3 > CO 3 2 >> F respectively. Overall, distribution pattern of all the major ions may be ranged as HCO 3 > Cl > Na + > Ca +2 > SO 4 2 > NO 3 > Mg +2 >CO 3 2 >>K + > F. 3.1 Physicochemical Parameters of Ground Water: Hydrogen ion concentration (ph) of the ground water is varying from 7.23 to 7.96 with an average value of These values are within the permissible limit prescribed by ICMR (as ) and WHO (as ). Electrical conductivity values are observed between 570 and 2470 microsiemens cm 1 (µs cm 1 ) with a mean of 1456 µs cm 1 at 30 C. The EC values for sample no. S19, S21, S25, S27, S28, S29, S32, S33, S34, S35 and S36 exceed the permissible limit prescribed by WHO as 1400 µs cm 1. According to Wilcox (1955) classification of ground water on the basis of electrical conductivity, 19 samples are found in permissible category while sample no. S23 and S33 were ranged into good and doubtful categories respectively for irrigation purposes as mentioned in Table 1a, 1b and 2. The values of total dissolved solids are ranged from 299 to 1320 mg L 1 with a mean value of 768 mg L 1. The TDS values for sample no. S19, S20, S21, S25, S27, S28, S29, S32, S33, S34, 368

3 RESEARCH ARTICLE ISSN S35, S36 and S38 have exceeded the permissible limit of WHO (as 600 mg L 1 ). The total hardness is mainly due to calcium and magnesium ions (Tatawat and Chandel, 2007). TH values of the ground water samples are varying from to mg L 1 with a mean value of mg L 1. The TH content in all the samples are within permissible limit prescribed by WHO (as 500 mg L 1 ) and ICMR (as 600 mg L 1 ) with the exception of sample no.s29 and S33. The total alkalinity values are varied from to mg L 1 with an average value of mg L 1. Dissolved oxygen is an important parameter for water purity and it depends on the temperature and organic content in the samples (Srivastava and Ramanathan, 2008). DO content of samples have ranged from 5.4 to 6.9 mg L 1 with an average value of 6.5 mg L 1 at 30 C. Table 1a: Ground water chemistry in eastern part of Sikar city S.N. S19 S20 S21 S22 S23 S24 S25 S26 S27 S28 S29 S30 ph TDS EC TH TA Na K Ca Mg Cl SO 4 2 HCO CO 3 ND ND ND ND F NO DO RSC SAR %Na PI CAI

4 RESEARCH ARTICLE ISSN Note: The value of all parameters are expressed in mg L 1 except EC (µs cm 1 ), ph, RSC, SAR, %Na, PI and CAI. ND means not detectable. Calcium concentrations of samples are ranging between and mg L 1 with a mean value of mg L 1. All the samples are within permissible limit prescribed by WHO (as 100 mg L 1 ) with exemption of sample no.s19, S21, S29, S35 and S36. Magnesium content is ranged from 4.81 to mg L 1 with an average value of mg L 1. The observed magnesium concentrations are below the permissible limit prescribed by ICMR (as 200 mg L 1 ). In the study area, some water samples have exposed the salty taste due to higher content of sodium along with chloride. The sodium content in the ground water samples ranges from to mg L 1 with a mean value of mg L 1. Potassium content is varied from 1.42 to 6.91 mg L 1 with an average value of 3.75 mg L 1. Table 1b: Ground water chemistry in eastern part of Sikar city S.No. S31 S32 S33 S34 S35 S36 S37 S38 S39 Avg. Min. Max. ph TDS EC TH TA Na K Ca Mg Cl SO HCO CO ND ND ND F NO DO RSC SAR %Na PI CAI

5 RESEARCH ARTICLE ISSN Carbonate and bicarbonate contents are varying from 3.54 to and to mg L 1 with an average value of and mg L 1 respectively. Chloride content in the study area is varied from to mg L 1 with an average value of mg L 1. The chloride content in sample no S19, S20, S21, S27 S28 S29, S32, S33, S34 and S36 has crossed the permissible limit prescribed by WHO (as 250 mg L 1 ). According to Stuyfzand (1989) classification of ground water based on the chloride concentration, 12 and 3 samples are in brackishsalt and salt categories respectively as summarized in Table 1a, 1b and 2. Sulfate content is varied from to with a mean value of mg L 1. The sulfate values of all ground water samples are under the permissible limit prescribed by ICMR (as 200 mg L 1 ) and WHO (as 250 mg L 1. The ground water pollution due to nitrate is increasing in India. The sources of nitrate pollution are mainly point sources (i.e. poultry farms, cattle shed and leakage from septic tanks etc.) and non point sources like nitrogenous fertilizers etc. (Rao 2006). The nitrate content is varying from 6.15 to mg L 1 with a mean value of mg L 1 as NO 3. The sample no S29, S33, S35 and S38 have crossed the permissible limit prescribed by WHO (50 mg L 1 as NO 3 ). Fluoride concentration less than 1 mg L 1 in drinking water has beneficial effect on human body but higher content causes serious dental and skeletal fluorosis (Chhabra, 2008 & Shyam and Kalwania, 2011). The fluoride content is found between 0.33 and 3.87 mg L 1 with an average value of 1.19 mg L 1 and sample no. S27, S31, S34 and S39 have crossed the permissible limit of 1.5 mg L 1 prescribed by WHO. 3.2 Statistical Representation of Ground Water Parameters The physicochemical parameters of ground water are further analyzed for different statistical parameters as shown in Table 1a and 1b. The ground water classifications, based on these physicochemical and statistical parameters are summarized in Table 2. Richard (1954) has classified water on the basis of sodium absorption ratio (SAR). SAR is an important parameter for determination of soil alkalinity or alkali hazards in the use of ground water for irrigation purposes (Kumaresan and Raiyazuddin, 2006). The value of SAR can be calculated by the following formula. Where, all ionic concentrations are expressed in terms of meq L 1. All the ground water samples in eastern part of Sikar city are in excellent category for irrigation purposes with exception of sample no. S37 as summarized in Tables 1a, 1b and 2. Richard has also determined the hazardous effect of carbonate and bicarbonates on water quality in terms of residual sodium carbonate (RSC). It can be determined by a formula as RSC= (CO HCO 3 ) (Ca +2 + Mg +2 ) Where, all ionic concentrations are expressed in terms of meq L 1. According to this classification, 17 and 2 samples are found in good and medium categories respectively while sample no. S22 and S37 are ranged in bad category for agricultural purposes as specified in Tables 1a, 1b and

6 RESEARCH ARTICLE ISSN The soil permeability is influenced by long term use of irrigation water and sodium, calcium, magnesium, bicarbonate content of the soil (Raju, 2007). Doneen (1964) has evolved a formula, permeability index (PI) to measure the soil permeability for assessing the suitability of water for irrigation purposes. It can be determined as Where, all ionic concentrations are expressed in terms of meq L 1. In the study area, 14 ground water samples are categorized into classii and remaining 7 samples are ranged into classi as mentioned in Tables 1a, 1b and 2. Table 2: Classifications of ground water in eastern part of Sikar city Classification Pattern Categories Ranges No. of Samples %age of Samples Sodium Absorption Ratio (SAR) (Richard 1954) Excellent Good Fair Poor > Percent Sodium (%Na) (Wilcox 1955) Excellent Good Permissible Doubtful Unsuitable > Residual Sodium Carbonate(RSC) (Richard 1954) Good Medium Bad < > Electrical Conductivity (EC) (Wilcox 1955) Excellent Good Permissible Doubtful Unsuitable < > Permeability Index (PI) (Doneen 1964) ClassI ClassII > ChloroAlkaline Indices (CAI) (Schoeller 1967) Chloride (Cl ) (Stuyfzand 1989) Base Exchange Reactions Cation anion Exchange Reactions ExtremelyFresh Very Fresh Fresh Fresh Brackish Brackish Brackish Salt Salt Hyper Saline Negative value Positive value < >

7 RESEARCH ARTICLE ISSN Schoeller (1967) has evolved a formula, Chloro alkaline indices (CAI) to know the ion exchange between the ground water and its surroundings during residence or travelling in the aquifer. The CAI can be measured as CAII = [Cl (Na + +K + )]/Cl Where, all ionic concentrations are expressed in terms of meq L 1. The negative value of CAI indicates that there is exchange between sodium and potassium (Na + +K + ) in water with calcium and magnesium (Ca +2 +Mg +2 ) in the rocks by a type of baseexchange reactions. The positive value of CAI represents the absence of baseexchange reactions and existence of cationanion exchange type of reactions (Raju, 2007). In the study area, 14 samples have the negative value of CAI proving the baseexchange reactions while 7 samples indicate the cationanion exchange reactions as summarized in Tables 1a, 1b and 2. Sodium content is generally expressed in terms of percent sodium or soluble sodium percentage. Wilcox (1955) planned a method for rating the irrigation waters based on percent sodium and electricalconductivity. The percent sodium is calculated by the formula as Where, all ionic concentrations are expressed in terms of meq L 1. In the study area, 2 and 15 water samples are found in good and permissible categories respectively but 4 samples are ranged into doubtful category for the purpose of irrigations, as summarized in Tables 1a, 1b and Correlation Matrix Table 3: Correlation matrix (Spearman's Rank Correlation Coefficient) ph EC TDS TH K + Na + Ca +2 Mg +2 Cl F SO 4 2 ph CO 3 2 HCO 3 NO EC TDS TH K Na Ca Mg Cl F SO CO HCO 3 NO

8 RESEARCH ARTICLE ISSN A correlation analysis is a bivariate method that describes the degree of relationship between two variables For this purposes, Spearman's rank correlation coefficient has been calculated using quality parameters of ground water samples in eastern part of Sikar city as shown in Table 3. Spearman's rank correlation coefficient is denoted by ρ (rho) and its value will always be between 1.0 and A positive ρ corresponds to an increasing while a negative ρ corresponds to a decreasing monotonic trend between two water quality parameters. A high correlation coefficient (near 1 or 1) means a good relationship between two variables and its value around zero means no relationship between them (Srivastava, 2008). In the study area (Table 3), ph shows negative correlation with most of the variables. The better positive correlation between ph and CO 3 2 indicates that ph of the samples is due to carbonate ions. The value of EC indicates the good positive correlation with most of the variables such as TDS, Cl, TH, Ca +2, Na + and SO 4 2. The good positive correlation was observed between Ca +2 and TH, K + and SO 4 2, Na + and Cl, Ca +2 and Cl, Ca +2 and SO 4 2, Cl and SO 4 2. The pairs like ph and Ca +2, ph and TH, CO 3 2 and HCO 3 have good negative correlation. 3.4 Graphically Representation of Physicochemical Parameters The Durov (1948) diagram is an alternative form of the Piper trilinear diagram. Durov plots the major ions as percentage of meq L 1 in two base triangles and total cations and total anions are set equal to 100%. The data points in the two base triangles are projected into square of the main field which lies perpendicular to the third axis in each triangle. It shows clustering of water quality data points and finally displays some possible geochemical processes that could affect the water genesis. Mg +2 Symbol Cations Anions (Na + +K + ) HCO 3 Cl Ca +2 SO 4 2 Figure 1: Durov Plot for ground water parameters in eastern part of Sikar city 374

9 RESEARCH ARTICLE ISSN The final result of this diagram (Figure 1) specifies that most of the ground water samples in the study area show no dominant cation or anion indicating water exhibiting simple dissolution or mixing. Water type of 4 samples is dominated by Ca +2 and HCO 3 ions representing an important ion exchange process while one sample is dominated by SO 2 4 and Na + ions indicating probable mixing influences. The total concentration of soluble salt or salinity hazard in irrigation water can be expressed in terms of electrical conductivity (EC). Sodium concentration is an important parameter because it reacts with soil to reduce its permeability by replacing other cations. The extent of this replacement (sodium hazards) has been expressed by SAR (sodium absorption ratio) or percent sodium (%Na). U.S. salinity laboratory (USSL) has designed a diagram to interpreting the combined effect of salinity and sodium hazards. Very High High Medium S4 S3 S SAR Low S1 Sodium (alkali) Hazard Electrical Conductivity (µs cm 1 ) C1 C2 C3 C4 Symbol Low Medium High Very High Salinity Hazard Figure 2: USSL diagram for ground water parameters in eastern part of Sikar city Waters have been divided into C1, C2, C3, and C4 categories on the basis of salinity hazard and S1, S2, S3 and S4 categories on the basis of sodium hazard. According to USSL diagram, most of the ground water samples have the high salinity and low or medium alkalinity (sodium) hazards as shown in Figure 2. The results indicate that 12 and 6 out of 21 ground water samples are found in C3S1 class with high salinity and low sodium hazards and C3S2 class with high salinity and medium alkalinity hazards respectively. The ground water of these samples can be used for irrigation with most crops under special management for salinity control due to high salinity hazards. It is classified that one sample in C4S1 class is 375

10 RESEARCH ARTICLE ISSN not suitable for irrigation water under ordinary conditions due to very high salinity hazard. In the study area, one sample in C2S1class can be used for irrigation with most crops on most soils but one sample in C3S3 class can t be used for irrigation without special practices for salinity and alkalinity control. The Schoeller (1965) diagram is used to study the comparative changes in the concentrations and ratios of water quality parameters for different samples. The different water quality parameters are plotted along with their concentrations (meq L 1 ) as shown in Figure 3. Results specify that lines of similar slope connecting concentrations of different parameters are indicative of water from a similar source. The most water type of high sodium content also has high concentration of chloride. Concentration (meq L 1 ) Ca +2 Mg +2 Na + Cl 2 SO 4 Parameters HCO 3 NO 3 F Figure 3: Schoeller Plot for ground water parameters in eastern part of Sikar city. The water samples can be divided into two types on the basis of sodium content, one type has low sodium content in the range meq L 1 and other has high sodium content in the range meq L Conclusions The analysis revealed that most of the samples in the eastern part of Sikar city is slightly alkaline and brackish salty. The distribution pattern of all major ions (based on the average value in mg L 1 ) in the ground water is found in the order HCO 3 > Cl > Na + > Ca +2 > SO 4 2 > NO 3 > Mg +2 > CO 3 2 >> K + > F. More than half samples are not found suitable for drinking purposes (TDS > 600 mg L1). The other water quality parameters such as Mg +2, CO 3 2, HCO 3, SO 4 2 and DO are ranged within permissible limit. The chloride ion concentration of nearly half of total samples is more than 250 mg L 1. Approximately 20 percent samples have the fluoride level more than 1.5 mg L 1 and nitrate level more than 50 mg L 1 showing the need to aware the public not to use particular ground water for drinking purposes. Results indicate that the water samples taken from municipal area are more contaminated compare to their surrounding area. This variation in concentration may be due to either recharging of contaminated water in heavily populated and industrialized area or increasing depth level. The SAR values hinted out that these samples belong to excellent category for irrigation purposes. The percent sodium level of samples indicated that approximately 19% samples are 376

11 RESEARCH ARTICLE ISSN doubtful whereas, 71% samples are in permissible category of the sodium hazards for irrigation purposes. The CAI values of approximately 67% samples in the study area are related to the base exchange type of reaction and remaining 33% samples are associated with the cationanion exchange type of reactions. The Durov diagram specifies that most of the samples show no dominant cation or anion indicating water exhibiting simple dissolution or mixing. The Schoeller diagram assured that most of the samples have similar ground water source. Furthermore, USSL diagram stated the C3S1 and C3S2 class for most of the samples. These samples are suitable for irrigation purposes under special management for salinity control due to high salinity. Acknowledgements: We are thankful to the Institute for providing necessary facilities to complete this study. One of the authors, Radhey Shyam is also thankful to ONGC, Mumbai Region for giving the permission to carry out the research and posting him in 14 days on/off pattern at offshore. 5. References 1. APHA, (1989). Standard methods for the examination of water and waste water, 17 th Ed. American public Health Association, American Water Works Association, Water Pollution Control Federation, Washington D.C. 2. Begum A., Krishna, H. S. and Khan, I., 2009, Analysis of heavy metals in water, sediments and fish samples of Madivala lakes of Bangalore, Karnataka, International Journal of Chem Tech Res, 1(2), pp Blais J. F., Tyagi R. D. and Aucleir J. C., 1993, Bioleaching of metals and sewage sludge: effect of temperature, Water Resource, 27(1), pp Central Ground Water Board (CGWB), , Annual report and other related reports on ground water quality, Central Ground Water Board, New Delhi. 5. Central Public Health and Environmental Engineering Organization (CPHEEO), 1998, A manual on water supply and treatment, Akalank Publication, New Delhi. 6. Chhabra V. K., 2008, A manual on water, waste water and material analysis, Indian Water Works Association (IWWA), Jaipur. 7. Doneen L. D., 1964, Notes on water quality in agriculture. Published as a Water Science and Engineering Paper 4001, Department of Water Science and Engineering, University of California. 8. Durov S. A., 1948, Natural waters sand graphic representation of their composition, Dok. Akad Nauk SSSR, 59, pp Gajendra C. and Thamarai P., 2008, Study on statistical relationship between ground water quality parameters in Namibiyar river basin, Tamil Nadu, India, Pollution. Research, 27(4), pp

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