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Corresponding Author: M.A. Gomaa, Department of Hydrogeochemistry, Desert Research Center, El Matariya, Cairo, Egypt.19
Applications of Hydrogeochemical Modeling to Evaluate Quaternary Aquiferin the Area Between Idfu and Aswan, Eastern Desert, Egypt
M.A. Gomaa, M.M. Emara, M.M.B. El-Sabbah and S.A. Mohallel1 2 2 1
Department of Hydrogeochemistry, Desert Research Center, El Matariya, Cairo, Egypt1
Department of Chemistry, Faculty of Science, Al-azhar University, Cairo, Egypt2
Abstract: Application of the software package Mass-Balance Model (NETPATH for windows) to evaluategroundwater quality is the main target in this study. NETPATH was used to perform a variety of aqueousgeochemical calculations including; the saturation indices (SI) of the major mineral phases, testing of watercorrosivity, influencing of the River Nile on the groundwater and to apply water mixing models. To achieve themain target of the article, twenty-one groundwater samples representing the Quaternary aquifer, beside twosurface water samples were collected from the study area and chemically analyzed. The hydrochemical resultsshow that, the groundwater salinity increases eastward, where its quality varies between fresh in the west andslightly saline due east. Also groundwater varies from soft to highly hard. The saturation indices of the majormineral phases in the investigated groundwater samples show that:
Most of groundwater are supersaturated with respect to iron mineral phases (hematite, goethite..etc).Such minerals reflect the sensitivity of iron to oxidation even in low concentrations.Groundwater is supersaturated with respect to the main carbonate minerals (calcite, aragonite anddolomite).Groundwater is supersaturated with respect to quartz and chalcedony, such minerals are consideredindicators for erosion of dolomite as well as aluminum silicates that built up the local soils (feldspars,kaolinite and micas).Groundwater is supersaturated with respect to chrysotile, sepiolite, talc and rhodochrosite. This reflectsthe leaching effect of soil materials due to weathering of the surrounding rocks as well as agriculturalactivities.The investigated groundwater varies from mild corrosion (19%), faint coating forming in the majority ofsamples (67%) up to mild scale forming (14%).The contribution of recent recharge from Nile water to the Quaternary aquifer is noticed in the study areaand varies from moderate to high.
Distributions of saturation indices for calcite, dolomite and gypsum indicate that the Quaternarydevelopment strength becomes weak from west to East. Mass balance approach interprets quantitatively theevolution of groundwater chemistry. Those results are very helpful to understand groundwater system in thefuture study. Nitrate concentrations in considerable mountainous groundwater were significantly elevated inresponse to increasing anthropogenic land uses toward the west. Also, mixing model was conducted betweenwater from different sources. The obtained results reflect that, the mixing can be used as an effective methodfor water treatment (in particular, lowering nitrate levels).
INTRODUCTION organisms, color, turbidity, no radiochemical nor
Mostly, groundwater is more desirable than surface The area under investigation lies within the transition partwater for many reasons, as absence of pathogenic between Eastern Desert and Nile valley covering about
biological contaminations as well as its great storage.
IDFU
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Gab al Mi d ri k
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rc R in g C o m p le x - E sse nt ia l ly al k a l ine sy e n i te kt T r a ch y t e Plu gs an d She etsW a d i N a t a s h vo l ca n i cs - D o m in a n t lya l k a lin e b a s a l t an d a n d esi t e
ku U nd efer e nt ia t ed U p p e r Cre t a ce o u sin cl u d e s c la sti cs an d p hos phates o f t h e D u w i F o rm a t ion (Kd u) kdu D U W I (p hosphate) For ma t i on - C a m p a n i a n t o M aa str ic h t ian .
A l t er n a t ing Phosph ate , Sh a le , ma r ls to n e a n d Oyste r li m esto n e .kn
an d Qu sei r V a ri eg a t ed S h a leN U B IA Gr ou p - C am p a n i a n o r o ld er T a re f San ds tone
gy Y O U N G ER G R A N IT O IDS - G a tt a r ian G r an ite a n d a l lpost -te ct o n i c g ra n i t e gr a n o d io r ite a n d a d a me ll i te
dv D O K H A N V O L C A N I C S - S l igh t ly m e ta m o rp hoseda n d e s ite , p o rp h y r ite , an d p y r o cl as t ic r oc ks
g o O L D E R G R A N I TO I D S - Syn tec to n i c t o l a te te ct o n icas Gr e y G ra n i t e, S h ai t ian Gra n i t e, o r O l d e r Gr an ite.
md M ET A G A B BR O-D IO RIT E C O M PL E X - G a b b r oid an dd o l er i ti c m as ses , te ct o n i s e d , Urali tised, an d a f fe cte d b y o lde r g ra n i t o ids.
sp S E R P E N T I N I TE - S e rpe nt in ite , t a l c ca rb on ate , an d r el a t ed ro c k s.
mv SH A D L I M ET A V O LC A N I C S - Fissu re er up t i on s o f surfac eo r subm a rin e effus iv e s r ep r es ente d by re gi o n a ll y m e ta m o rph os edrhy o l ite , da ci t e, a n d e s ite , ba sa lt a n d p y r oc la st i c ro c ks.
m s GE O S Y N C L I N A L M ET A S E D IM E N TS - A w id e ra n g e o fli t h o lo g i ca l ty pes in cl u d in g b i o ti t e an d c h l o ri te s chi sts.
gn M IG IF - HA FAF IT PA R A G N E I S S A N D M IG M A T IT E -Psa m m it i c ho rnbl en de an d b io t it e g n e iss a n d m i gma t i t e
FA U L T
kv
gravel-fill and mud-fill.Quaternary - Older Nile deposits,
Intl. J. Water Resources & Arid Environ., 3(1): 19-34, 2014
20
Fig. 1: wells' location map of Quaternary aquifer in the study area
Fig. 2: Geologic map of the study area (Modified after geologic map of Aswan quadrangle, Egypt 1978)
22500 km (Figure 1). It is limited by Latitudes 24°00 & 25° main groundwater resource in the study area. It is mainly2 '
12 N and Longitudes 32°55 & 35 48 E. It is dominated by composed of gravels, sands and silts with clay' ' '
the flood plain and characterized by a gentle topographic intercalations, varies in thickness from 40 to 120 m. It isslope towards Nile River. It has a wide range of geologic subjected to semi-confined conditions due to thetime from Pre-Cambrian to Recent (Figure 2). Its climate is overlying silty clay layer. The depth to water surfacehot, dry and rainless in summer and being mild with rare ranges from 2m (Nos. 8, 13, 14 &18) to 8.4 m (No. 2),rainfall in winter (0.7 mm) as recorded in Aswan (Table 1). The amount of water in this aquifer is low andGovernorate [1]. The Quaternary aquifer represents the represented by water lenses mostly accumulated from
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Table 1: Depth to groundwater surface of the Quaternary aquiferWell No. Water point name Wadi Depth to water (m)2 Muweilha W. Muweilha 8.47 Sameh W. El Kharit 38 Ahmed Huseen W. El Kharit 29 Yousef W. El Kharit 2.511 Hesham W. El Kharit 2.512 Shaban W. El Kharit 313 - W. El Kharit 214 El Mashtal W. Midrik 215 El Warsha W. Midrik 2.516 - W. Midrik 3.517 - W. Midrik 2.518 - W. Midrik 220 El Asfalt W. Midrik 327 Umm Khrus El Sheikh El Shazly 5.533 - W. abbadi 335 El Haj Gamal W. abbadi 337 Zakalona - 338 Zakalona - 439 Zakalona - 440 Zakalona - 5.541 Zakalona - 5
past rainy periods [2]. The main source of recharge is chemically for major and some minor constituents.the direct precipitation, return flow after irrigation and The analyses were performed in the central lab, Desertflush floods coming from the mountainous region. The Research Center (DRC), Egypt, according to the methodshydraulic conductivity of the investigated aquifer in the adopted by the United States Geological Survey [4],central portion is about 80 m/day [3]. methods of determination for inorganic substances in
RESULTS AND DISCUSSION descriptive statistics of the chemical parameters
Groundwater Chemistry: Twenty-one groundwater deviation) for the collected samples were calculated andsamples representing the Quaternary aquifer, besides illustrated (Table 4 & Figure 3). According to thetwo surface water samples were collected in hydrochemical analyses data, the following could beOctober 2010 from the study area and analyzed deduced:
water and fluvial sediments [5, 6], (Tables 2 & 3). The
(minimum, maximum, mean, median and standard
Table 2: Hydrochemical analyses data of the investigated groundwater samples in mg/l, (2011)Sample No pH Temp.°C E.C TDS mg/l Ca Mg Na K CO HCO SO Cl3 3 4
Fig. 3: Descriptive statistics of the investigated groundwater samples
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The groundwater temperature ranges between 25.9°C(No. 39) in Zakalona area and 31.3°C (Nos. 15, 16 and17) in Wadi Midrik, where the aquifer is mainlysubjected to the atmospheric pressure (phreaticaquifer).pH values of the examined groundwater samplesrange from 7.2 (No. 41) in Zakalona area to 8.2 (No.15) in Wadi Midrik, reflecting a neutral to slightlyalkaline groundwater.The ground water salinity has a wide range from154.4 mg/l at Wadi El Kharit (No. 11) to 12563 mg/l atWadi Abbadi (No. 33), reflecting fresh to salinecategories. It is clear that 57% of water samples arefresh (Nos. 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18 & 20),29% of total samples are brackish (Nos. 27, 35, 37, 38,39 & 40) while 14% of the total samples are saline Fig. 4: Relationship between Salinity and Hardness in(Nos. 2, 33 & 41). Salinity values decrease due west the Quaternary groundwatertoward the cultivated land in the study area. This ismainly due to the dilution processes from the program for simulating chemical reactions and transportirrigation surface water. processes in natural or polluted water. The program isIt is clear that, the mean values of total, based on equilibrium chemistry of aqueous solutionspermanent and temporary hardness reaches interacting with minerals, gases, solid solutions,195.52, 34.65 and 259.25 mg/l as CaCO , exchangers and sorption surfaces.3
respectively in the fresh groundwater and 1676.5,1549.5 and 126.99mg/l, respectively in the brackish Chemical Equilibrium and Saturation Indices (SI):groundwater and 4159.08, 4036.09 and 122.98mg/l, The quality of the recharge water and its interactions withrespectively in saline to highly saline groundwater. soil and rocks during its percolation, movement andThese data indicate an increase in total and storage in the aquifers represent the key factors in thepermanent hardness with the increase of water groundwater chemistry. These interactions involve mainlysalinity and vice versa in case of temporary the chemical reactions and their results through bothhardness, (Figure 4). This is mainly attributed to the dissolution and precipitation processes, which areeffect of leaching and dissolution of soluble salts controlled by the solubility products of the differentwhich lead the increase of hardness with particular involved mineral phases.importance to the effect of NaCl on increasing Generally, the saturation indices are used tosolubility of Ca and Mg in water [7, 8] taking into express the water tendency towards precipitation or2+ 2+
consideration the contribution of the CO and longer dissolution. The degree of water saturation with2
residence time as well as the influence of salty water respect to a mineral is given by: SI = log (K / K ),and cation exchange processes. where K is the ionic activity product, K is theAlkalinity ranges between 25.27 mg/l as CaCO (No. solubility product and SI is the saturation index of3
33) in Wadi Abbadi to 564.74 mg/l as CaCO (No. 15) the concerned mineral. When SI is equal to zero, the3
in Wadi Midrik. water is at equilibrium or saturated with the mineral
Geochemical Modeling: The software package NETPATH under-saturation and that the mineral phase tends tofor windows, [9], (Figure 5) is used to evaluate the dissolve, whereas SI over zero (positive value)subsurface geochemical processes and provides an indicates super-saturation and that the mineral phaseindication of the reaction potential of the system, also it tends to precipitate. The saturation indices (SI) of theis used to perform a variety of aqueous geochemical major mineral phases in the investigated groundwatercalculations including the saturation indices (SI) of the samples were calculated using the software packagemajor mineral phases, testing of water corrosivity and to (NETPATH-WIN). The obtained results (Table 5 andapply water mixing models. NETPATH is a computer Figure 6) reflect that:
IAP SP
IAP SP
phase, SI less than zero (negative value) indicates
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Fig. 5: Data base and NETPATH opening pages in the NETPATH-Win Model, (after El-Kadi et al., 2010)
Fig. 6: Saturation indices with respect to minerals in the investigated groundwater samples
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Table 5: Saturation indices of minerals in the study area
Saturation indices of minerals--------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Saturation indices of minerals-----------------------------------------------------------------------------------------------------------------------------------------------------------------
The groundwater is supersaturated with respect to the surrounding rocks as well as agriculturalthe main carbonate minerals (calcite, aragonite anddolomite) nearly at the most samples. This is clearwhere the pH values reflect slightly alkalinecharacter. The main source of CO in this aquifer is2
the atmosphere when reacts with rain water to formbicarbonate ion in addition to leaching of carbonatematerials.The groundwater is supersaturated with respect toquartz and chalcedony. Quartz and chalcedony areindicators for erosion of aluminum silicates that builtup the local soils composed of feldspars, kaoliniteand micas [10].The groundwater is supersaturated with respect toiron mineral phases (hematite, goethite..etc).Hematite, goethite and Fe(OH ) reflect iron3
sensitivity to oxidation, even in low concentrations.The groundwater is supersaturated with respect tochrysotile, sepiolite and talc. This reflects theleaching effect of soil materials due to weathering of
activities.Results of saturation indices using WATEQFPcontained in NETPATH are plotted (Figures 7, 8 & 9).From these isograms, it is clear that the trends ofvariation in the saturation indices of differentminerals were nearly similar. The values of theindices are smaller in the recharge area if comparedwith those in the downgradient area. Those isogramsprovide information on the recharge and residenttime (water-minerals reaction time) of groundwater[11].Within Quaternary aquifer, groundwater seems to beundersaturated with respect to gypsum (Fig. 9). It isundersaturated with respect to calcite and dolomitein the west area and oversaturated in the east area.This indicates that dissolution ability of groundwateris stronger in west than east. It can be inferred hereinthat the Quaternary aquifer development strengthwould become weak from west to east from the pointof view of chemical thermodynamics, [11].
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Fig. 7: Isogram of SI in Quaternary aquiferCalcite
Fig. 8: Isogram of SI in Quaternary aquiferDolomite
As mentioned before, the groundwater samples dilution caused by the mixing of the Quaternaryare undersaturated with respect to Gypsum and groundwater with surface water which commonlyoversaturated with Calcite and Dolomite (Figures 7, 8 & 9). has a low salinity and a Ca-HCO major ion composition,The main reason for such widespread should be the [12].
3
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Fig. 9: Isogram of SI in Quaternary aquiferGypsum
Corrosivity and Scale Formation: Corrosion is a complex According to the saturation indices of minerals in theseries of reactions between water and metal surfaces as investigated groundwater samples (Table 7) as indicatorwell as materials in which the water is stored or of water corrosivity or scale forming, the following couldtransported. The corrosion process is an oxidation/ be deduced:reduction reaction that returns refined or processedmetals to their more stable ore state. The primary concerns The majority of groundwater samples (67%) are faintof the corrosion potential of water include the potential coating. Faint coating in the municipal wells (Nos. 7,presence of toxic metals as lead and copper, deterioration 8, 9, 12, 13, 14, 15, 16, 18, 20, 38, 39, 40 & 41) mayand damage of the household plumbing as well as (by the time) lead to clog the pipes, which transportaesthetic problems such as; stained laundary, bitter taste the water to the inhabitants, so, treatment is stronglyand greenish-blue stains around basins and drains. In soft recommended.water, corrosion occurs due to the lack of dissolved About 19% of the investigated groundwater samplescations such as calcium and magnesium, while in hard are mild corrosion (Nos. 11 in Wadi El Kharit, 17 inwater a precipitate or coating of calcium or magnesium Wadi Midrik, 33 & 35 in Wadi Abbadi).carbonate accumulate on the internal wall of pipes. About 14% of the investigated groundwater samplesThis coating can inhibit the corrosion of the pipe, because are mild scale forming (Nos. 2 in Wadi Muweilha, 27it acts as a barrier, but it can also clog the pipe. Water in El Sheik El Shazly & 37 in Zakalona area).with high levels of sodium, chloride, or other ions willincrease water conductivity and promoting corrosion [12]. Mass Balance Approach [11]: Mass balance ofSaturation indices were used as an indicator of water groundwater composition was simulated along the twocorrosivity or scale formation. Table (6) presents a typical paths (I and II) mentioned above (Figure 1). Path I is fromrange of SI of calcite that may be encountered in a initial samples Nos. 14, 15 & 20 at northwest to finaldrinking water and a description of the nature of the water sample No. 12 at southeast, while path II is from initialas well as the general recommendations regarding samples Nos. 2&27at east to the final samples No. 35 attreatment [13]. west.
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Table 6: Classification of water corrosion potential based on the calcite saturation indices values and recommended treatments
Saturation indices (SI) Description General recommendations Saturation indices (SI) Description General recommendations
-5.0 Severe corrosion Treatment recommended 0.5 Some faint coating Treatment typically not needed-4.0 Moderate corrosion Treatment recommended 1.0 Mild scale forming Some aesthetic problems-3.0 Moderate corrosion Treatment recommended 2.0 Mild scale forming Some aesthetic – considered-2.0 Moderate corrosion Treatment should be considered 3.0 Moderate scale forming Treatment should be considered-1.0 Mild corrosion Treatment should be considered 4.0 Severe scale forming Treatment probably required-0.5 Mild corrosion Treatment probably not needed 5.0 Severe scale forming Treatment required0.0 Balanced Treatment typically not needed - - -
Table 7: Classification of groundwater samples in the study area based on its tendency to be corrosive
Table 8: Mass Balance Model for Quaternary groundwater aquifer
Path I Path II---------------------------------------------------------------------- ---------------------------------------------------------------------
Mineral Phase Initial to Final Process Initial to Final Process
Aragonite 0.33 Dissolution -3.23 PrecipitationCalcite 0 Dissolution -3.23 PrecipitationDolomite -0.48 Precipitation -2.64 PrecipitationGypsum 0 Dissolution -8.41 PrecipitationNaCl -1.13 Precipitation -33.75 PrecipitationPyrite - - -3.1 PrecipitationKaolinite - - - -Quartz - - - -Ca-Na Exchange -0.64 Na Exch. In the mineral -17 Na Exch. In the mineral and
and Ca released into groundwater Ca released into groundwaterGoethite -0.01 Precipitation 3.1 DissolutionCO gas -0.66 released -6.5 released2
The results of modeling I show that groundwater Influence of River Nile on the Quaternary Aquifer:dissolves aragonite, calcite and gypsum from initial The first initial water is sample No. 35 which represents(water) points to final point, while dolomite, halite and the Quaternary aquifer, the second initial water is thegoethite tend to precipitate along this path. Ca-Na ion sample S1 from the River Nile and the third initial water isexchange occurs where Na is exchanged in the mineral the sample R1 from rain water (Table 9). The contributionand Ca is released into groundwater. In addition, of recent recharge from the River Nile to the Quaternarygroundwater dissolves only the goethite from initial aquifer in the study area varies from low to high.(water) points to final point in Path II, while aragonite, Also, plotting groundwater samples of thecalcite, dolomite, gypsum, halite and Pyrite are Quaternary aquifer on Trilinear diagram (Figure 10)precipitated along this path. Ca-Na ion exchange occurs showed that, some samples are clustered around the River(Table 8). The results indicate a groundwater flow from Nile sample (inside the circle), indicating the effect ofeast to west (more chemical reactions, Path II). leakage on their chemistry [12]. In addition, all samples
CaNa+K HCO3+CO3
Cl
20
40
60
80
20
40
60
80
SO4
20
40
60
80
20
40
60
80
Mg
Legend
S1 River Nile sampleGroundwater sample
20S1
11 147 16
12 17
15
13
2
8
18
20 2040 4060 6080 80
9
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Fig. 10: Trilinear diagram for the Quaternary groundwater samples
located inside the circle are highly similar in water type ages [14], which resulted from the mixing between(HCO - Na for all). Such similarity between these samples different water types.3
reflects high degree of mixing between various sources of Nitrate concentrations in groundwater were restrictedwaters [14]. to a low range in areas higher than 250 m a.s.l. (Figure 12).
Effect of Nitrate Concentration: The Quaternary regions (Nos. 27, & 35). The extent of nitrategroundwater samples had a wide range of nitrate contamination is dramatically increased in the lower areasconcentrations from 8.55mg/l (No. 9) to 75.55 mg/l (No. 41) (Figure 11). This increase represents a change in land use(Table 3), with standard deviation of about 22.32. This from largely natural cover to residential and agriculturalfeature can be attributed to the different groundwater area [15].
This feature is more clearly shown in the mountainous
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Fig. 11: Isogram of Nitrate distribution in Quaternary aquifer
Fig. 12: Digital Elevation Model (DEM) of the study area
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Table 10: The concentration of nitrate in samples (15 & 38) after mixing with samples (S1, S2 & 18)Sample Sample (15) (60.63 mg NO /L) Sample (38) (76.74 mg NO /L)3 3
Mixing Models: The mix samples generate concentrations In this model, the water samples (Nos. 15 and 38)as a result of the step-wise mixing of specified proportions were mixed with Nile water (S1), irrigation canal water (S2)of two selected samples from the investigated samples. and water sample (No. 18). The mixing model in thisThe parameters that will be included in the mixing section mainly aims to lower the chemical content of watercalculations could be selected (typically you should sample (No. 15) for using it in drinking, irrigation andselect parameters that you know are common to each industrial targets by mixing with Nile water, water ofsample). Such mixings can show that the evolution of the irrigation canal or fresh water sample (No. 18). The modelbrackish water is possibly due to hydraulic mixing of fresh aims also to lower the high nitrate concentration in theand saline waters within the aquifer matrix and/or in well water samples (No.15 and 38) to a level below themixing. In this section, mixing models were conducted acceptable level of nitrates for drinking water (45 mg/l)between water from different sources as a proposed with the same mixing samples. The mixing could be donesolution for lowering the chemical content, specially in the house cisterns, the roof tanks and in the pools.nitrate levels in the highly contaminated wells to the The averaged chemical composition of the water samplesacceptable limits. For mixing each of the input solutions, (Nos. 15 and 38) was mixed with different percentagesit is multiplied by its mixing fraction and a new output (0.9: 0.1, 0.8: 0.2,…., 0.1: 0.9) from water samples (Nos. S1,solution is calculated stoechiometrically [16]. S2 and 18). The changes in the nitrate concentration in
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the water samples (Nos. 15 and 38) as a result of the indicators for erosion of dolomite as well asmixing processes are summarized (Table 10), while thechanges in the concentrations of the major cations andanions are tabulated (Tables 11 & 12).
Table (10) shows that, 30% or less mixing percentageof water samples (Nos. 15 and 38) with 70% or more ofmixing water (Nos. S1, S2 and 18) is necessary to lowernitrate concentration in the water even to less thanacceptable level of nitrate (45 mg/l) in drinking water.Nitrate content is only an example of the watercharacteristics that could be improved and controlled bymixing, thus mixing could be considered as an effectivewater treatment method. Mixing is used also for loweringthe total salinity (TDS) of the saline water in the desert orin the coastal areas by mixing with fresh water samples touse it in industrial and agricultural projects.
CONCLUSIONS
Recently, several approaches includinghydrogeochemistry and modeling have been used toinvestigate the Quaternary groundwater system in thearea between Idfu and Aswan, Eastern Desert, Egypt.The software package Mass-Balance Model, NETPATHfor windows was used to perform a variety of aqueousgeochemical calculations including; the saturation indices(SI) of the major mineral phases, testing of watercorrosivity, influencing of the River Nile on thegroundwater and to apply water mixing models.
To achieve the main target of the article, twenty-onegroundwater samples representing the Quaternary aquifer,beside two surface water samples were collected from thestudy area and chemically analyzed.
The hydrochemical results show that, thegroundwater salinity increases eastward, where its qualityvaries between fresh in the west and slightly saline dueeast. Also groundwater varies from soft to highly hard.
The saturation indices of the major mineral phases inthe investigated groundwater samples show that:
Most of groundwater are supersaturated with respectto iron mineral phases (hematite, goethite..etc). Suchminerals reflect the sensitivity of iron to oxidationeven in low concentrations.Groundwater is supersaturated with respect to themain carbonate minerals (calcite, aragonite anddolomite).Groundwater is supersaturated with respect to quartzand chalcedony, such minerals are considered
aluminum silicates that built up the local soils(feldspars, kaolinite and micas). Groundwater is supersaturated with respect tochrysotile, sepiolite, talc and rhodochrosite. Thisreflects the leaching effect of soil materials due toweathering of the surrounding rocks as well asagricultural activities.The investigated groundwater varies frommild corrosion (19%), faint coating forming inthe majority of samples (67%) up to mild scaleforming (14%).The contribution of recent recharge from Nile waterto the Quaternary aquifer is noticed in the study areaand varies from moderate to high.
Distributions of saturation indices for calcite,dolomite and gypsum indicate that the Quaternarydevelopment strength becomes weak from west to East.Mass balance approach interprets quantitatively theevolution of groundwater chemistry. Those results arevery helpful to understand groundwater system in thefuture study. Nitrate concentrations in considerablemountainous groundwater were significantly elevated inresponse to increasing anthropogenic land uses towardthe west.
Also, mixing model was conducted between waterfrom different sources. The obtained results reflect that,the mixing can be used as an effective method for watertreatment (in particular, lowering nitrate levels).
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