Influence of hydrogeochemical processes on temporal changes in groundwater quality in a part of Nalgonda district, Andhra Pradesh, India

Influence of hydrogeochemical processes on temporal changes in groundwater quality in a part of Nalgonda district, Andhra Pradesh, India R. Rajesh, K. Brindha, R. Murugan & L. Elango

Environmental Earth Sciences ISSN 1866-6280 Volume 65 Number 4 Environ Earth Sci (2012) 65:1203-1213 DOI 10.1007/s12665-011-1368-2

1 23

Your article is protected by copyright and all rights are held exclusively by SpringerVerlag. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your work, please use the accepted author’s version for posting to your own website or your institution’s repository. You may further deposit the accepted author’s version on a funder’s repository at a funder’s request, provided it is not made publicly available until 12 months after publication.

1 23

Author's personal copy Environ Earth Sci (2012) 65:1203–1213 DOI 10.1007/s12665-011-1368-2

ORIGINAL ARTICLE

Influence of hydrogeochemical processes on temporal changes in groundwater quality in a part of Nalgonda district, Andhra Pradesh, India R. Rajesh • K. Brindha • R. Murugan L. Elango

•

Received: 2 March 2011 / Accepted: 17 September 2011 / Published online: 8 October 2011 Ó Springer-Verlag 2011

Abstract Geochemical processes that take place in the aquifer have played a major role in spatial and temporal variations of groundwater quality. This study was carried out with an objective of identifying the hydrogeochemical processes that controls the groundwater quality in a weathered hard rock aquifer in a part of Nalgonda district, Andhra Pradesh, India. Groundwater samples were collected from 45 wells once every 2 months from March 2008 to September 2009. Chemical parameters of groundwater such as groundwater level, EC and pH were measured insitu. The major ion concentrations such as Ca2?, Mg2?, Na?, K?, Cl-, and SO42were analyzed using ion chromatograph. CO3- and HCO3concentration was determined by acid–base titration. The abundance of major cation concentration in groundwater is as Na? [ Ca2? [ Mg2? [ K? while that of anions is HCO3- [ SO42- [ Cl- [ CO3-. Ca–HCO3, Na–Cl, Ca– Na–HCO3 and Ca–Mg–Cl are the dominant groundwater types in this area. Relation between temporal variation in groundwater level and saturation index of minerals reveals the evaporation process. The ion-exchange process controls the concentration of ions such as calcium, magnesium and sodium. The ionic ratio of Ca/Mg explains the contribution of calcite and dolomite to groundwater. In general, the geochemical processes and temporal variation of groundwater in this area are influenced by evaporation processes, ion exchange and dissolution of minerals. Keywords Hard rock  Saturation Index  PHREEQC  Evaporation  Dissolution of minerals

R. Rajesh  K. Brindha  R. Murugan  L. Elango (&) Department of Geology, Anna University, Chennai 600025, India e-mail: [email protected]; [email protected]

Introduction Groundwater chemistry of a region is generally not homogeneous and it is controlled by geochemical processes, flow and recharge processes, evaporation, evapotranspiration and possible presence of contamination sources. Identification of various geochemical processes will help to understand the causes for changes in water quality due to the interaction with aquifer material, especially in weathered rock formations. Hydrogeochemical studies in turn assist in planning management and remedial measures to protect aquifers that are contaminated by natural and anthropogenic activities. Thus, detailed knowledge on geochemical process that control groundwater chemistry is very essential to understand and deal with the groundwater related issues. The cause for the changes in groundwater quality by anthropogenic activity like agriculture is also an important issue in arid and semiarid region. The geochemical properties of groundwater depend on the chemistry of water in the recharge area as well as on the different geological processes that take place in the subsurface. The groundwater chemically evolves due to the interaction with aquifer minerals or by the intermixing among the different groundwater reservoirs along the flow path in the subsurface (Domenico 1972; Wallick and Toth 1976). Jalali (2005) reported that the dissolution of carbonate minerals, cation exchange and weathering of silicates control the groundwater chemistry in semiarid region of western Iran. Martinez and Bocanegra (2002) indicated that cation exchange and calcite equilibrium are the important hydrogeochemical processes that control the groundwater composition. Hydrochemical processes such as dissolution, weathering of carbonate minerals and ion exchange are responsible for groundwater quality in Delhi, India (Kumar et al. 2006). Singh et al. (2008) indicated the impact of mining allied activities on groundwater quality in the upper

123

Author's personal copy 1204

catchment of Damodar River basin, India. Even though there are several studies on hydrogeochemical processes in the arid region of alluvial and basaltic terrain no major research has been carried out in arid regions of granitic terrain. Implication of irrigation activity, evaporation and geochemical processes of granitic aquifers need to be understood. The granitic terrain of Archean age found in most part of the central southern India is one such area with arid climate and irrigation activity. The present study was carried out in granitic terrain of part of Nalgonda district, Andhra Pradesh, India. The Nalgonda district in South India is well known for high concentration of fluoride in groundwater (Rao 1991). Influence of aquifer materials, availability of fluoride rich minerals and intense weathering processes have accentuated the release of fluoride from rocks and soils to groundwater under the alkaline environment in Wallipalli watershed, Nalgonda district, Southern India (Reddy et al. 2010). Hydrogeochemical exploration for targeting unconformity related uranium mineralization in Kurnool Group sediments located southeast of Nalgonda district was carried out by Singh et al. (2002). Other studies in this area concentrated only on fluoride, nitrate (Brindha et al. 2010, 2011) and bromide (Brindha and Elango 2010) concentration in groundwater. However, no research had been carried out to identify the hydrogeochemical processes based on regular monitoring of groundwater level over space and time. Hence, the present study was carried out in a part of Nalgonda district, Andhra Pradesh (Fig. 1), with an objective of identifying the influence of hydrogeochemical processes on temporal changes in groundwater quality. Fig. 1 Location of the study area

123

Environ Earth Sci (2012) 65:1203–1213

Materials and methods The geology of the region was studied by numerous geological field visits. The rock types were identified by megascopic observation of outcrops and well sections. Based on these field investigations the geological map obtained from Geological Survey of India was modified. The subsurface geology and intensity of weathering was studied by the inspection of large diameter unlined wells. The thicknesses of soil zone and weathered granite were measured in the vertical section of this large diameter wells. Further two 60-m deep borehole logs were acquired from Atomic Minerals Division, India. Groundwater samples were collected once every two months from March 2008 to September 2009 from 45 sampling wells (Fig. 2) which were selected on the basis of a detailed well inventory survey. About 450 samples were collected from open wells and bore wells during the monitoring period. Groundwater levels in these wells were measured using a water level recorder (Sonalist 101). Chemical parameters such as pH, electrical conductivity (EC) and temperature of the groundwater samples were measured in the field using portable multiparameter instrument (YSI 556). Groundwater samples were collected in clean polyethylene bottles of 600 ml capacity. The sampling bottles were soaked in 1:1 diluted HCl solution for 24 h prior to sampling and then washed with distilled water. They were washed again before each sampling with the filtrates of the sample. In the case of bore wells, water samples were collected after pumping the water for about 10 min. In the case of open

Author's personal copy Environ Earth Sci (2012) 65:1203–1213

1205

Fig. 2 Location of monitoring wells

wells care was taken to collect the samples 30 cm below the water table using a depth sampler. Samples collected were transported to the laboratory and filtered using 0.45 lm Millipore filter paper for further analysis. The major cations and anions such as Na?, K?, Ca2?, Mg2?, Cl- and SO42- of groundwater samples were determined using Metrohm 861 advanced compact ion chromatograph using appropriate standards. The concentration of CO3and HCO3- were determined by titrating against H2SO4 as per standard method (APHA 1995). The quality of the analysis was ensured by standardization using blank, spike and also with duplicate samples. Further accuracy of the chemical analysis was verified by calculating ion balance error which was generally within 5%. Soil samples were collected near the sampling wells in May 2009 at a depth of 30 cm from ground surface. CaCO3 of the soil samples were determined by acidimetric titration method (Menon 1979). TDS (Total Dissolved Solids) for Gibbs diagram was calculated by using the formula TDS = EC 9 0.64. The geochemical data were processed using PHREEQC 2 (Parkhurst and Appelo 1999) to determine the saturation index (SI) of minerals and evaporation modeling. Description of the study area The study area (Fig. 1) is located at a distance of about 135 km ESE of Hyderabad. The southeastern side of the study area is surrounded by the Narajuna Sagar reservoir and the southern side of the area is partly bounded by Pedda Vagu River. The northern boundary is bounded by Gudipalli Vagu River. This area experiences arid to semiarid climate. The study area goes through hot climate during the summer (March–May) with a temperature

ranging from 30 to 46.5°C and in winter (November–January) it varies between 16 and 29 Æ C. The average annual rainfall in this area is about 1,000 mm occurring mostly during southwest monsoon (June–September). Paddy is the principle crop grown in this area while other crops include sweet lime, castor, cotton, grams and groundnut. Drip irrigation is practiced in this area especially for sweet lime. The commercial crops like chilies, cotton and groundnut are also grown in this area mostly by using groundwater. Geology and hydrogeology The topography derived from SRTM (Shuttle Radar Topography Mission) data is shown in Fig. 3. The topography of the area comprising of an undulating terrain has a maximum elevation of 348 m on northwestern side and minimum elevation of 170 m on the eastern side. In general, the ground surface slopes towards southeast direction. There are several small hillocks in this area with height ranging from 100 to 200 m. The surface runoff has resulted into the development of dendritic to sub-dendritic drainage pattern in this area. The geological map of the study area was prepared after GSI (1995). This primarily comprises of granite and granitic gneisss (Fig. 4). These rocks are generally medium to coarse-grained. These rocks are traversed by numerous dolerite dykes and quartz veins. The granitic rocks are intensely weathered and the thickness of weathered zone ranges from 4 to 15 m. Calcareous material like calcrete was observed in the weathered zone of several large diameter wells. In certain regions calcrete was also observed in ground surface and rock exposures. Occurrence of calcrete and nodular forms of calcrete was also reported from the neighboring watershed by Reddy et al.

123

Author's personal copy 1206

Environ Earth Sci (2012) 65:1203–1213

Fig. 3 Topography

Fig. 4 Geology

(2010). The Srisailam Formation is the youngest member of the Cuddapah supergroup, directly over the basement granite with a distinct unconformity. The quartzite of Srisailam Formation is exposed in the southeastern part of the study area. The meta sediments of Srisailam Formation which include pebbly-gritty quartzite, shale, dolomitic limestone, intercalated sequence of shale-quartzite and massive quartzites. The top soil, weathered rock and fractured rock acts as an unconfined aquifer in this area. The pore spaces are developed in the weathered portions to form potential water-bearing zones. There are a number of wells in this area which supply water for domestic and agricultural

123

purposes. The depth of the dug wells ranges from 1.45 m to 20 m below ground level. Thus most of the wells tap groundwater is from the weathered and fractured zone. The diameter of the dug wells ranges from 2 to 5 m. The bore wells were generally of 15 cm diameter and they were of depth greater than 10 m. The borehole data of a few wells are shown in Fig. 5. This figure shows the lithology of open wells in which the thickness of soil and weathered zone were measured during the field investigation. However, the boreholes in the quartzite region drilled for exploratory purpose by the Indian Atomic Minerals Division are of 60 m deep. Rainfall is the major source of groundwater recharge in this area. The groundwater level fluctuates

Author's personal copy Environ Earth Sci (2012) 65:1203–1213

1207

Fig. 5 Lithologs of selected boreholes

between 0 to 12 m and the average fluctuation is by about 6 m during 2008–2009. Sometimes during extreme summer few wells become completely dry. Out of 450 measurements made in 45 wells over ten visits, 8% of measurements indicated dry condition. In general groundwater flows towards the southeastern direction of the study area. The hydraulic conductivity of the area is 2.2–15.1 m/day. The specific yield of the aquifer ranges from 0.1 to 0.15. Even though there are several intrusives in this area, they are not functioning as a barrier due to the high intensity of weathering. The groundwater level of open wells located on both sides of an intrusive rock was compared and it was found to comply with the fact that these intrusive do not play a significant role as a barrier (Fig. 6). This figure also show similar trend in EC of groundwater of open wells across the dolerite intrusive.

Thus groundwater of this area is generally alkaline in nature. EC of the groundwater samples ranges from 375 to 2500 lS/cm. The general order of dominance of cations in the groundwater of the study area is Na? [ Ca2? [ Mg2? [ K? while that for anions is HCO3- [ SO-2 4 [ Cl [ CO3 . Ca–HCO3, Na–Cl, Ca–Na–HCO3 and Ca–Mg–Cl are the dominant water types in this area based on the Piper (1944) classification (Fig. 7). According to Gibbs diagram (Gibbs 1970) rock water interaction is responsible for the chemical composition of the groundwater (Fig. 8). The temporal variation of chemical composition, groundwater level and rainfall of monitoring wells are shown in Fig. 9. This figure indicates that the concentration of ions vary with respect to time. The rainfall recharge and other hydrogeological processes are the causes for this variation. Hydrogeochemical processes

Results and discussion The minimum and maximum values of chemical parameters and concentration of major ions measured in groundwater of this area are given in Table 1. The pH of the groundwater samples of this area ranges from 6.9 to 7.8.

The results from the hydrochemical data were used to identify the geochemical processes and mechanisms responsible for the groundwater chemistry of the study area. The identified processes are explained in detail in the following sections.

123

Author's personal copy 1208

Environ Earth Sci (2012) 65:1203–1213

Fig. 6 Temporal variations in groundwater level and EC in wells across the intrusive

Table 1 Minimum and maximum values of physical and chemical parameters Parameters

Minimum

Maximum

Groundwater level (m bgl)

0

14.6

pH

6.9

7.8

EC (lS/cm)

375

2,500

Na (mg/l)

21

470

Ca (mg/l)

15

409

Mg (mg/l)

4

94

K (mg/l) CO3 (mg/l)

BDL 0

317 48

HCO3 (mg/l)

44

592

SO4 (mg/l)

1

405

Cl (mg/l)

0

355

with the evaporation line of groundwater of lowest ionic concentration (well no. 3 in November 2008). These plots indicate that groundwater chemistry of this area is controlled by evaporation process. Direct evaporation of groundwater is possible as the region has many number of large diameter open wells where groundwater table occur at shallow depths. Ion-exchange process In order to evaluate the ion-exchange process in this region, a plot of Na–Cl versus Ca ? Mg–HCO3–SO4 was prepared (Fig. 12). If ion exchange is the dominant process in the system the points will form a line with a slope of -1 which can be explained by the following reaction (1) (Rajmohan and Elango 2004).

Evaporation process

Ca2þ ðMg2þ Þ þ Naþ Clay $ 2Naþ þ CaðMgÞClay

In general, the evaporation process would cause an increase in concentration of all mineral species in water. The plot of Na versus Cl (Fig. 10) and Ca versus HCO3 (Fig. 11) of groundwater collected from the study area was compared

Similar results were observed for the groundwater of this area. The plot shows that the points give a line with a slope of -0.8794. This confirms that Ca2?, Mg2? and Na? concentrations are interrelated through ion exchange

123

ð1Þ

Author's personal copy Environ Earth Sci (2012) 65:1203–1213

1209

Fig. 7 Geochemical facies of groundwater

Fig. 8 Mechanism of controlling groundwater chemistry

(Rajmohan and Elango 2004; Elango et al. 2003; Fisher and Mullican 1997). Silicate weathering Silicate weathering is one of the major processes that release Na and K in groundwater in aquifers of plutonic

rocks. This is likely to be the major process that contributes Na and K to groundwater. Sample points below 1:1 line in Na versus Cl scatter diagram (Fig. 13) indicate that they are derived by silicate weathering (Stallard and Edmond 1983). Similarly Ca ? Mg Versus Total cations (TC) scatter diagram (Fig. 14) indicates that most of the samples lie below the 1:1 line. This also indicates the contribution

123

Author's personal copy 1210

Environ Earth Sci (2012) 65:1203–1213

Fig. 11 Relationship of Ca versus HCO3 along with evaporation line of groundwater with lowest ionic concentration

Fig. 12 Relationship between Na–Cl and Ca?Mg–HCO3–SO4

Fig. 9 Temporal variations of chemical composition, groundwater level and rainfall

Fig. 13 Relationship between Na and Cl

Fig. 10 Relationship of Na versus Cl along with evaporation line of groundwater with lowest ionic concentration

123

Fig. 14 Relationship between Ca ? Mg and Total Cation (TC)

Author's personal copy Environ Earth Sci (2012) 65:1203–1213

1211

of Na and K to groundwater by silicate weathering. This may be explained by the following weathering reaction (2).

level even after 100% of evaporation. It is expected that calcite and dolomite may have been deposited in the soil

2NaAlSi3 O8 þ 2H2 CO3 þ 9H2 O ) Al2 Si2 O5 ðOHÞ4 ðAlbiteÞ

ðSilicate weatheringÞ

ðKaoliniteÞ þ 2Naþ þ 4H4 SiO4 þ 2HCO 3

Similar processes of weathering of pyroxene, amphibole and calcic feldspar minerals, which are common in basic rocks that are easily weatherable, controlled the concentration of these ions in groundwater in certain other parts of southern India and in Himalyan river basin (Jacks 1973; Bartarya 1993). Dissolution of minerals Mineral equilibrium calculations for groundwater are useful in predicting the presence of reactive minerals in the groundwater system and estimating the mineral reactivity (Deutsch 1997). The SI of mineral is calculated using SI = (IAP/Ks) (Appelo and Postma 1996), where IAP is the ion activity product and Ks is the solubility product of the mineral. SI of minerals is very helpful for evaluating the groundwater chemistry and to see if it is controlled by equilibrium with solid phases (Appelo and Postma 1996). If SI \ 0, the water is undersaturated, if SI = 0, the water is in equilibrium with the mineral and if SI [ 0, the water is oversaturated. The SI of all minerals were calculated using PHREEQC by assuming that the groundwater of lowest concentration of ions is evaporated. It was found that the SI of calcite and dolomite increases to more than zero when water is evaporated by 40 and 70%, respectively (Fig. 15). All the other minerals do not reach saturation

Fig. 15 Calculated changes in SI of minerals during evaporation of groundwater with lowest ionic concentration

ð2Þ

zone and well sections due to evaporation. Presence of such calcareous material was noted in the well sections of this area and also in the neighboring watershed of similar geological condition by Reddy et al. (2010). The CaCO3% of 26 soil samples collected from this area ranges from 0.4 to 27.3%. Jacks and Sharma (1995) also reported the occurrence of dolomitic carbonates in this area. They also observed preferential formation of calcite in the chromusters while dolomite occurs only in the Rhodustalfs. The soils in the Nalgonda region are of moderately to gently sloping Ustrothents and Rhodustalfs (Gajbhiye and Mandal

Fig. 16 Temporal variations in rainfall, groundwater level and mineral saturation index

123

Author's personal copy 1212

Environ Earth Sci (2012) 65:1203–1213

Conclusion

Fig. 17 Relationship between Ca/Mg versus Total Cation (TC)

2000). Hence, it is reasonable to assume that these minerals are reactive in groundwater environment and they can control solution concentration. The SI of calcite and dolomite of groundwater of this area vary with time. During recharge of rainfall, the groundwater level increases and SI of calcite and dolomite decreases (Fig. 16). During dry periods, when the groundwater level decreases, the SI of these minerals increases which indicates the process of evaporation. That is, the recharge of rainwater dissolves these minerals deposited during the preceding dry months in the soil zone, which increases the SI of minerals in groundwater. If the rainfall continues for an extended period, the saturation levels continues for an extended period, the saturation levels of minerals decrease in groundwater. Similar observation was made in a few other regions of south India (Elango and Ramachandran 1991; Rajmohan and Elango 2004). As it is an arid dry land where irrigation is practiced with both surface and groundwater, the water used for irrigation undergoes evaporation leading to increase in concentration of ions. This evaporation enriched irrigated water enters the groundwater zone as recharge, which is pumped again for irrigation. Thus pumping of groundwater for irrigation and its evaporation from the irrigated area lead to increase in concentration of salts especially carbonates in the soils. Modeling of evaporation processes by PHREEQC also indicates that water reaches the saturation level only for the minerals of Calcite and Dolomite (Fig. 16). The study of the Ca/Mg ratio of groundwater from this area also supports the dissolution of calcite and dolomite (Fig. 17). That is, if the ratio of Ca/Mg = 1, dissolution of dolomite should occur, whereas a higher ratio is indicative of greater calcite contribution (Maya and Loucks 1995; Jacks and Sharma 1995). Higher Ca/Mg molar ratio ([2) indicates the dissolution of silicate minerals, which contributes calcium and magnesium to groundwater. In this plot, the points closer to the line (Ca/Mg = 1) indicate the dissolution of dolomite. Most of the samples which have a ratio between 1 and 2 indicate the dissolution of calcite. Those with values greater than 2 indicate the effect of silicate minerals (Fig. 17).

123

The geochemical processes of groundwater in a part of Nalgonda district, Andhra Pradesh, India were assessed by systematic collection and analysis of groundwater samples from March 2008 to September 2009. The dominant hydrogeochemical facies of groundwater is Ca–HCO3, Na–Cl, Ca–Na–HCO3 and Ca–Mg–Cl. Weathering and dissolution of silicate minerals control the concentration of major ions such as Na?, Ca2?, Mg2? and K? in groundwater of this area. Ion exchange process also controls the concentration of Ca2? and Na?. Relation between groundwater level and saturation index of minerals reveals the importance of evaporation process on groundwater ionic concentration and irrigation practice in this arid region. The temporal variation in groundwater chemistry of this area is principally controlled by a combination of factors such as evaporation, ion exchange, silicate weathering and dissolution of minerals. The variation in groundwater chemistry helped in the identification of geochemical processes in this hard rock region. Acknowledgments The authors would like to thank the Board of Research in Nuclear Sciences, Department of Atomic Energy, Government of India (Grant No. 2007/36/35) for their financial support. Thanks are due to Atomic Mineral Division for providing the litholog numbers, YLR 31 and YLR 14. The Department of Science and Technology’s Funds for Improvement in Science and Technology scheme (Grant No. SR/FST/ESI-106/2010) and University Grants Commission’s Special Assistance Programme (Grant No. UGC DRS II F.550/10/DRS/2007(SAP-1)) are also acknowledged as the analytical facilities created from these funds were used to carry out part of this work.

References APHA (1995) Standard methods for the examination of water and wastewater, 19th edn. American Public Health Association, Washington, DC Appelo CA, Postma D (1996) Geochemistry, groundwater and pollution. Balkema, Rotterdam Bartarya SK (1993) Hydrochemistry and rock weathering in a subtropical lesser Himalayan river basin in Kumaun, India. J Hydrol 146:149–174 Brindha K, Elango L (2010) Study on bromide in groundwater in parts of Nalgonda district, Andhra Pradesh. Earth Sci India 3(1):73–80 Brindha K, Murugan R, Rajesh R, Elango L (2010) Natural and anthropogenic influence on the fluoride and nitrate concentration of groundwater in parts of Nalgonda district, Andhra Pradesh, India. J Appl Geochem 12(2):231–241 Brindha K, Rajesh R, Murugan R, Elango L (2011) Fluoride contamination in groundwater in parts of Nalgonda district, Andhra Pradesh, India. Environ Monit Assess 172:481–492 Deutsch WJ (1997) Groundwater geochemistry: fundamentals and application to contamination. CRC, Boca Raton Domenico PA (1972) Concepts and models in groundwater hydrology. McGraw Hill, New York

Author's personal copy Environ Earth Sci (2012) 65:1203–1213 Elango L, Ramachandran S (1991) Major ion correlations in groundwater of a coastal aquifer Journal of Indian Water Resources Society 11:54–57 Elango L, Kannan R, Senthilkumar M (2003) Major ion chemistry and identification of hydrogeochemical processes of ground water in a part of Kancheepuram district, Tamil Nadu, India. Environ Geosci 10(4):157–166 Fisher SR, Mullican WF (1997) Hydrogeochemical evolution of sodium-sulfate and sodium-chloride groundwater beneath the northern Chihuahua desert, Trans-Pecos, Texas, USA. J Hydrogeo 5(2):4–16 Gajbhiye, KS, Mandal C (2000) Agro-Ecological Zones, their Soil Resource and Cropping Systems, Status of Farm Mechanization in India, Cropping Systems, Status of Farm Mechanization in India, pp 1–32 Gibbs RJ (1970) Mechanisms controlling world water chemistry. Science 170:795–840 GSI (1995) Geological Survey of India’s Geology and minerals map of Nalgonda district, Andhra Pradesh, India Jacks G (1973) Chemistry of groundwater in a district in Southern India. J Hydro 18:185–200 Jacks G, Sharma VP (1995) Geochemistry of calcic horizons in relation to hillslope processes, southern India. Geoderma 67:203–214 Jalali M (2005) Major ion chemistry of groundwaters in the Bahar area, Hamadan, Western Iran. J Env Geo 47:763–772 Kumar M, Ramanathan AL, Rao MS, Kumar B (2006) Identification and evoluation of hydrogeochemical processes in the groundwater environment of Delhi, India. J Env Geo 50:1025–1039 Martinez DE, Bocanegra EM (2002) Hydrogeochemistry and cation exchange processes in the coastal aquifer of Mar Del Plata. Argentina. J Hydrogeo 10:393–408 Maya AL, Loucks MD (1995) Solute and isotopic geochemistry and groundwater flow in the Central Wasatch Range. UtahJ Hydro 172:31–59 Menon RG(1979) Physical and chemical methods of soil analysis, A laboratory manual prepared for the use of technicians working in

1213 the soil laboratories of the FAO/UNDP/URT project ‘‘National Soil Service’’ (English), FAO, Rome (Italy), Agriculture Department 188 Parkhurst DL, Appelo CAJ (1999) A computer program for speciation, batch-reaction, one-dimensional transport and inverse geochemical calculations: Water resource investigation, US Geological Survey, a report, pp 99–4259 Piper AM (1944) A Graphical interpretation of water- analysis. Trans Am Geophys Union 25:914–928 Rajmohan N, Elango L (2004) Identification and evolution of hydrogeochemical processes of groundwater environment in an area of the Palar and Cheyyar River Basins, Southern India. J Env Geo 46:47–61 Rao NVRM (1991) Hydro-geochemistry and fluoride in Nalgonda district of Andhra Pradesh, India. International symposium on applied geochemistry. Osmania University, Hyderabad, pp 255–261 Reddy DV, Nagabhushanam P, Sukhija BS, Reddy AGS, Smedly PL (2010) Fluoride dynamics in the granitic aquifer of the Wailapally watershed, Nalgonda District, India. J Chem Geo 269:278–289 Singh RV, Sinha RM, Bisht BS, Banerjee DC (2002) Hydrogeochemical exploration for unconformity-related uranium mineralization: example from Palanudu sub-basin, Cuddapah Basin, Andhrapradesh, India. J Geo Exp 76:71–92 Singh AK, Mondal GC, Kumar S, Singh TB, Tewary BK, Sinha A (2008) Major ion chemistry, weathering processes and water quality assessment in upper catchement of Damoda River basin, India. J Env Geo 54:745–758 Stallard RF, Edmond JM (1983) Geochemistry of the Amazon: the influence of geology and weathering environment on the dissolved load. J Geophy Res 88:9671–9688 Wallick EI, Toth J (1976) Methods of regional groundwater flow analysis with suggestions for the use of environmental isotope and hydrochemical data in groundwater hydrology, pp 37–64

123