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1.
As one of the most arid regions in the world, the study area, Zhangye Basin is located in the middle reaches of the Heihe River, northwest China. Besides aridity, rapid social and economic development also stimulates greater demand for water, which is gradually fulfilled by groundwater extraction. In this study, the conventional hydrochemical techniques and statistical analyses were applied to examine the major ions chemistry and hydrochemical processes of groundwater in the Zhangye Basin. The results of chemical analysis indicate that no one pair of cations and anions proportions is more than 50% in the groundwater samples of the study area. High-positive correlations were obtained among the following ions: HCO3 ?–Mg2+, SO4 2?–Mg2+, SO4 2?–Na+ and Cl?–Na+. TDS depends mainly on the concentration of major ions such as HCO3 ?, SO4 2?, Cl?, Mg2+ and Na+. The hydrochemical types in the area can be divided into two major groups: the first group includes Mg2+–Na+–HCO3 ?, Mg2+–Na+–Ca2+–HCO3 ?–SO4 2? and Mg2+–Ca2+–Na+–SO4 2?–HCO3 ? types. The second group comprises Mg2+–Ca2+–SO4 2? type, Mg2+–Ca2+–SO4 2?–Cl? type and Mg2+–Na+–SO4 2?–Cl? type. The ionic ratio plot and saturation index calculation suggests that the silicate weathering, to some extent, and evaporation are dominant factors that determine the major ionic composition in the study area.  相似文献   

2.
The study of groundwater hydrogeochemistry of a hard rock aquifer system in Thoothukudi district has resulted in a large geochemical data set. A total of 100 water samples representing various lithologies like Hornblende Biotite Gneiss, Alluvium Marine, alluvium Fluvial, Quartzite, Charnockite, Granite and Sandstone were collected for two different seasons and analyzed for major ions like Ca2+, Mg2+, Na+, K+, HCO3 ?, Cl?, SO4 2?, NO3 ?, PO4 ?, F? and H4SiO4. Statistical analysis of the data has been attempted to unravel the hidden relationship between ions. Correlation analyses and factor analyses were applied to classify the groundwater samples and to identify the geochemical processes controlling groundwater geochemistry. Factor analysis indicates that sea water intrusion followed by leaching of secondary salts, weathering and anthropogenic impacts are the dominant factors controlling hydrogeochemistry of groundwater in the study area. Factor score overlay indicate major active hydrogeochemical regimes are spread throughout the Eastern, Northwestern and Southeastern parts of the study area. The dominant ions controlling the groundwater chemistry irrespective of season are Cl?, Na+, Mg2+, Ca2+, SO4 2?, K+ and NO3 ?. An attempt has also been made to note the seasonal variation of the factor representations in the study area. This study also illustrates the usefulness of statistical analysis to improve the understanding of groundwater systems and estimates of the extent of salinity/salt water intrusion.  相似文献   

3.
河北汤泉地热流体水文地球化学特征及其成因   总被引：7，自引：5，他引：2       下载免费PDF全文
提要：汤泉位于河北省遵化市西北部,为山前丘陵地貌,地热资源丰富。本文通过对该地区地热流体研究发现：Na+、Ca2+、K+、Mg2+与SO2-4、HCO-3、Cl-、NO-3是该地区地下热水的主要成分,水化学类型主要为SO2-4-Na+型,属于未污染的天然弱碱性水;流体中F-含量平均为9.36 mg/l,远高于国家地下水质量标准ⅴ级;可溶性SiO2的含量可作为地热温标;地热流体总矿化度平均为782.33 mg/l,属于淡水;为中等腐蚀型水,不结碳酸钙垢,无CaSO4?2H2O垢和SiO2垢生成的可能;地热流体属于含岩盐地层溶滤的陆相沉积水;根据氢氧稳定同位素可知,河北汤泉地热流体主要来源于大气降水。  相似文献   

4.
A survey on quality of groundwater was carried out for assessing the geochemical characteristics and controlling factors of chemical composition of groundwater in a part of Guntur district, Andhra Pradesh, India, where the area is underlain by Peninsular Gneissic Complex. The results of the groundwater chemistry show a variation in pH, EC, TDS, Ca2+, Mg2+, Na+, K+, HCO3 ?, Cl?, SO4 2?, NO3 ? and F?. The chemical composition of groundwater is mainly characterized by Na+?HCO3 ? facies. Hydrogeochemical type transits from Na+–Cl?–HCO3 ? to Na+–HCO3 ?–Cl? along the flow path. Graphical and binary diagrams, correlation coefficients and saturation indices clearly explain that the chemical composition of groundwater is mainly controlled by geogenic processes (rock weathering, mineral dissolution, ion exchange and evaporation) and anthropogenic sources (irrigation return flow, wastewater, agrochemicals and constructional activities). The principal component (PC) analysis transforms the chemical variables into four PCs, which account for 87% of the total variance of the groundwater chemistry. The PC I has high positive loadings of pH, HCO3 ?, NO3 ?, K+, Mg2+ and F?, attributing to mineral weathering and dissolution, and agrochemicals (nitrogen, phosphate and potash fertilizers). The PC II loadings are highly positive for Na+, TDS, Cl? and F?, representing the rock weathering, mineral dissolution, ion exchange, evaporation, irrigation return flow and phosphate fertilizers. The PC III shows high loading of Ca2+, which is caused by mineral weathering and dissolution, and constructional activities. The PC IV has high positive loading of Mg2+ and SO4 2?, measuring the mineral weathering and dissolution, and soil amendments. The spatial distribution of PC scores explains that the geogenic processes are the primary contributors and man-made activities are the secondary factors responsible for modifications of groundwater chemistry. Further, geochemical modeling of groundwater also clearly confirms the water–rock interactions with respect to the phases of calcite, dolomite, fluorite, halite, gypsum, K-feldspar, albite and CO2, which are the prime factors controlling the chemistry of groundwater, while the rate of reaction and intensity are influenced by climate and anthropogenic activities. The study helps as baseline information to assess the sources of factors controlling the chemical composition of groundwater and also in enhancing the groundwater quality management.  相似文献   

5.
Twenty groundwater samples were collected from Enugu metropolis over two seasonal periods in order to characterize the groundwater and to determine its quality for domestic and irrigation purposes. The results show that groundwater of the area is strongly acidic to slightly alkaline in nature and varied from “soft water” to “moderately hard” water type. The major ionic trend is in the order Cl? > Na+ > HCO3 ? > K+ > Mg2+ > Ca2+ > SO4 2?and Mg2+ > Cl? > Na+ > K+ > Ca2+ > HCO 3 ?  > SO4 2? in abundance for dry and rainy seasons, respectively. The results also reveal that there is an increase in trend of the ionic concentrations during the dry season, which arises from weathering of the host rocks and anthropogenic activities. Two hydrochemical facies were identified, namely, Na+ –K+ –Cl? –SO4 2?and Ca2+ –Mg2+ –Cl? –SO4 2? , with Na+ –K+ –Cl? –SO4 2? as the dominant facies for the two seasons. Groundwater quality ranges from “very poor water” to “good water” and “water unsuitable for drinking purposes” to “good water” for the dry season and rainy season investigations, respectively. The groundwater is suitable for irrigation purposes for the two seasons.  相似文献   

6.
Groundwater survey has been carried out in the area of Gummanampadu sub-basin located in Guntur District, Andhra Pradesh, India for assessing the factors that are responsible for changing of groundwater chemistry and consequent deterioration of groundwater quality, where the groundwater is a prime source for drinking and irrigation due to non-availability of surface water in time. The area is underlain by the Archaean Gneissic Complex, over which the Proterozoic Cumbhum rocks occur. The results of the plotting of Ca2+ + Mg2+ versus HCO3 ? + CO3 2?, Ca2+ + Mg2+ versus total cations, Na+ + K+ versus total cations, Cl? + SO4 2? versus Na+ + K+, Na+ versus Cl?, Na+ versus HCO3 ? + CO3 2?, Na+ versus Ca2+ and Na+: Cl? versus EC indicate that the rock–water interaction under alkaline condition is the main mechanism in activating mineral dissociation and dissolution, causing the release of Ca2+, Mg2+, Na+, K+, HCO3 ?, CO3 2?, SO4 2? and F? ions into the groundwater. The ionic relations also suggest that the higher concentrations of Na+ and Cl? ions are the results of ion exchange and evaporation. The influences of anthropogenic sources are the other cause for increasing of Mg2+, Na+, Cl?, SO4 2? and NO3 ? ions. Further, the excess alkaline condition in water accelerates more effective dissolution of F?-bearing minerals. Moreover, the chemical data plotted in the Piper’s, Gibbs’s and Langelier–Ludwig’s diagrams, computed for the chloro-alkaline and saturation indices, and analyzed in the principal component analysis, support the above hypothesis. The groundwater quality is, thus, characterized by Na+ > Ca2+ > Mg2+ > K+: HCO3 ? + CO3 2? > Cl? > SO4 2? > NO3 ? > F? facies. On the other hand, majority of groundwater samples are not suitable for drinking with reference to the concentrations of TDS, TH, Mg2+ and F?, while those are not good for irrigation with respect to USSL’s and Wilcox’s diagrams, residual sodium carbonate, and magnesium hazard, but they are safe for irrigation with respect to permeability index. Thus, the study recommends suitable management measures to improve health conditions as well as to increase agricultural output.  相似文献   

7.
Hydrogeochemical studies have been carried out in a coastal region, using multivariate statistical model, for better understanding the controlling processes that influence the aquifer chemistry. Two principal components (PC1 and PC2) are extracted from the data set of chemical variables (pH, TDS, Ca2+, Mg2+, Na+, K+, HCO 3 ? , Cl?, SO 4 2? , NO 3 ? and F?), which account for 79% of the total variation in the quality of groundwater. The PC1 (salinity controlled process) includes the concentrations of TDS, Mg2+, Na+, K+, Cl?, SO 4 2? and NO 3 ? , while the PC2 (alkalinity controlled process) comprises the concentrations of pH, HCO 3 ? and F?. The spatial distribution of PC scores identifies the locations of high salinity and alkalinity processes. The first process corresponds to the influences of geogenic, anthropogenic and marine sources, and the second one to the influence of water-soil-rock interaction. Thus, the present study shows the usefulness of multivariate statistical model as an effective means of interpretation of spatial controlling processes of groundwater chemistry.  相似文献   

8.
The chemistry of the rainwater indirectly reflects the composition of the ions in the atmosphere. The study of the rainwater gains its own importance as it forms the basis for the agricultural, domestic and drinking water. Twelve rainwater samples were collected along the southeastern coast of India during southwest monsoon. The samples were analyzed for the major anions (Cl?, SO4 2?, PO4 3? and HCO3 ?) and cations (Na+, K+, Ca2+ and Mg2+). The majority of the samples reflect acidic pH. The general dominance of the cations is in the order of Na+ > Ca2+ > K+ > Mg2+ and that of anions is HCO3 ? > Cl? > SO4 2? > PO4 3?. The water is classified as calcium bicarbonate to sodium bicarbonate type. The decrease of pH value also increases the pCO2. In order to study the impact of acidic and alkaline species on rainwater, correlation coefficients were determined for establishing the relationship between different ions. Good correlation was established between cations, and sulfate has no correlation with other ions and pH. Factor analysis reveals that land use pattern, marine source and methanogenesis from the tidal influenced mangroves play a major role in determining the rainwater chemistry of the region.  相似文献   

9.
Hydogrochemical investigation of groundwater resources of Paragraph district has been carried out to assess the solute acquisition processes and water quality for domestic and irrigation uses. Fifty-five groundwater samples were collected and analyzed for pH, electrical conductivity, total dissolved solids, hardness, major anions (F?, Cl?, NO3, HCO3 ?, SO4 2?) and cations (Ca2+, Mg2+, Na+, K+). Study results reveal that groundwater of the area is alkaline in nature and HCO3 ?, Cl?, Mg2+, Na+ and Ca2+ are the major contributing ions to the dissolved solids. The hydrogeochemical data suggest that weathering of rock forming minerals along with secondary contributions from agricultural and anthropogenic sources are mainly controlling the groundwater composition of Pratapgarh district. Alkaline earth metals (Ca2++Mg2+) exceed alkalis (Na++K+) and weak acid (HCO3 ?) dominate over strong acids (Cl?+SO4 2?) in majority of the groundwater samples. Ca-Mg-HCO3 and Ca-Mg-Cl-HCO3 are the dominant hydrogeochemical facies in the groundwater of the area. The computed saturation indices demonstrate oversaturated condition with respect to dolomite and calcite and undersaturated with gypsum and fluorite. A comparison of groundwater quality parameters in relation to specified limits for drinking water shows that concentrations of TDS, F?, NO3 ? and total hardness exceed the desirable limits in many water samples. Quality assessment for irrigation uses reveal that the groundwater is good for irrigation. However, values of salinity, sodium adsorption ratio (SAR), residual sodium carbonate (RSC), %Na and Kelley index are exceeding the prescribed limit at some sites, demanding adequate drainage and water management plan for the area.  相似文献   

10.
Fifty groundwater samples were collected from Al-Hasa to analyze the pH, electrical conductivity (EC, dS m?1), total dissolved solids (TDS), major anions (HCO3?, CO32?, Cl?, SO42?, and NO3?), major cations (Ca2+, Mg2+, Na+, and K+), and total hardness. The analyzed data plotted in the Piper, Gibbs, and Durov diagrams, and water quality index (WQI) were calculated to evaluate the groundwater geochemistry and its water quality. The results reveal that most of the investigated samples are Ca2+, Mg2+, SO42?, Cl? and Na+, and HCO3? water types using the Piper diagram. Na+?>?Ca2+?>?Mg2+ are the dominant cations, while Cl??>?HCO3??>?SO42??>?CO32? are the dominant anions. Sodium adsorption ratio (SAR) values varied from 0.79 to 10; however, the Kelly ratio (KR) ranged between 0.1 and 2.2. The permeability index (PI) showed that well water is suitable for irrigation purposes with 75% or more of maximum permeability. The US salinity diagram revealed that the water quality classes of studied waters were CIII-SI, CIII-SII, and CIV-SII, representing height hazards of salinity and medium- to low-sodium hazard. The water quality index (WQI) results indicated that total dissolved solids are out of the drinking water standard limits in Saudi Arabia. The WQI revealed that 38% of the studied wells were considered as poor water (class III), 52% are found as very poor water class (IV), and 10% are unsuitable water for drinking class (V).  相似文献   

11.
Groundwater of an aquifer located in the vicinity of a large coal washery near Zarand City, Iran consists of two hydrochemically differing facies, which have been informally designated as groundwater (A) and groundwater (B). Groundwater (A) is native, brackish in composition and is characterized by Na+ > Mg2+ > Ca2+ > K+ and SO4 2? > HCO3 ? > Cl? > NO3 ?. Spearman’s rank correlation coefficient matrices, factor analysis data, and values of chloro-alkaline indices, C ratio and Na+/Cl? molar ratio indicate that in the groundwater (A), the ionic load of Ca2+, Mg2+, Na+, K+, SO4 2? and HCO3 ? is derived essentially from weathering of both carbonates and aluminosilicates and direct cation and reverse cation–anion exchange reactions. Groundwater (B) is the polluted variant of the groundwater (A), brackish to saline in composition, and unlike the groundwater (A), consists of HCO3 ? as the dominant anion. In comparison with the groundwater (A), the groundwater (B) contains higher concentrations of all ions, and its average ionic load (av. = 59.74 me/L) is 1.43 times higher than that of the groundwater (A) (av. = 41.54 me/L). Additional concentrations of Ca2+, Mg2+, K+, SO4 2?, Cl? and HCO3 ? in the groundwater (B) are provided mainly by downward infiltrating water from the coal washery tailings pond and reverse cation–anion exchange reaction between tailings pond water and exchanger of the aquifer matrix during non-conservative mixing process of groundwater (A) and tailings pond water. Certain additional concentrations of Na+, K+ and NO3 ? in the groundwater (B) are provided by other anthropogenic sources. Quality wise, both groundwaters are marginally suitable for cultivation of salt-tolerant crops only.  相似文献   

12.
Soils, rocks, altered rocks, hot and cold waters, and hot spring precipitates were sampled within and on the outskirts of geothermal fields in China. The contents of thirty trace elements in soils and rocks show that Hg, As, Sb, Bi, Li, Rb, Cs, Au, Ag, B, W, Sn, Pb, Zn, Mn, Ni and Co can serve as direct and indirect indicators for geothermal field exploration. Large amounts of data indicate that Hg, As and Sb are the best indicators of hot water sources. Altered rocks contain higher Hg, As, Sb, Bi and Be than unaltered rocks. Based on their abundances in hot waters, it is suggested that the following elements may be used as hydrochemical indicators of high-temperature hot-water geothermal systems: K+, Na+, Ca2+, Mg2+, SO2−4, HCO−3, F−, Cl−, SiO2, HBO2, CO2, pH, total dissolved solids and hydrochemical types, as well as Hg, As, Sb, Be, Li, Rb and Cs. Modern precipitates associated with hot springs have high contents of Ba, Be, Fe, Ti, Hg, As, Sb and Bi. Using these geochemical data, the authors have had much success in locating hot water drill sites within geothermal fields. Case histories are described for five geothermal areas.  相似文献   

13.
Soil salinization is an environmental problem having significant impacts on the soil–water–plant system. This problem is more frequent in coastal areas due to seawater intrusion into the land. Assessing the soil salinization is a critical issue for the agricultural areas situated in the Mediterranean basin. This paper examines the deterioration of soil quality in the cultivated land of a Mediterranean site (Agoulinitsa district—West Greece). Soil samples were collected in both pre-irrigation and post-irrigation seasons. Electrical conductivity (EC), pH and the ions Br?, Ca2+, Cl?, F?, K+, Li+, Mg2+, Na+, NH4 +, NO2 ?, NO3 ?, PO4 3? and SO4 2? were determined by the 1:2 (soil/water ratio on weight basis) method. The salts which were present in both seasons in the soils of the area studied are KCl, MgCl2, NaCl, CaSO4 and K2SO4. The wide spatiotemporal variation of EC in the cultivated land in both seasons demonstrates that soil salinity is controlled mainly by seawater intrusion and anthropogenic factors such as the application of salt-rich water which is directly pumped from the drainage ditches. Seawater intrusion provides the affected soil with elevated contents of Ca2+, Cl?, K+, Mg2+, Na+ and SO4 2?. Classification of the soils by using criteria given by the literature is discussed. Practices to prevent, or at least ameliorate, salinization in the cultivated land of Agoulinitsa district are proposed.  相似文献   

14.
The hydrogeochemical study of groundwater in Dumka and Jamtara districts has been carried out to assess the major ion chemistry, hydrogeochemical processes and groundwater quality for domestic and irrigation uses. Thirty groundwater samples were collected and analyzed for pH, electrical conductivity, total dissolved solids (TDS), total hardness, anions (F?, Cl?, NO3 ?, HCO3 ?, SO4 2?) and cations (Ca2+, Mg2+, Na+, K+). The analytical results show the faintly alkaline nature of water and dominance of Mg2+ and Ca2+ in cationic and HCO3 ? and Cl? in anionic abundance. The concentrations of alkaline earth metals (Ca2+?+?Mg2+) exceed the alkali metals (Na+?+?K+) and HCO3 ? dominates over SO4 2??+?Cl? concentrations in the majority of the groundwater samples. Ca?CMg?CHCO3 is the dominant hydrogeochemical facies in 60?% of the groundwater samples, while 33?% samples occur as a mixed chemical character of Ca?CMg?CCl hydrogeochemical facies. The water chemistry is largely controlled by rock weathering and ion exchange processes with secondary contribution from anthropogenic sources. The inter-elemental correlations and factor and cluster analysis of hydro-geochemical database suggest combined influence of carbonate and silicate weathering on solute acquisition processes. For quality assessment, analyzed parameter values were compared with Indian and WHO water quality standards. In majority of the samples, the analyzed parameters are well within the desirable limits and water is potable for drinking purposes. Total hardness and concentrations of TDS, Cl?, NO3 ? , Ca2+ and Mg2+ exceed the desirable limits at a few sites, however, except NO3 ? all these values were below the highest permissible limits. The calculated parameters such as sodium adsorption ratio, percent sodium (%Na) and residual sodium carbonate revealed excellent to good quality of groundwater for agricultural purposes, except at few sites where salinity and magnesium hazard (MH) values exceeds the prescribed limits and demands special management.  相似文献   

15.
Hydrogeochemical controlling factors for high rate of groundwater contamination in stressed aquifer of fractured, consolidated rocks belonging to semi-arid watershed are examined. The groundwater in mid-eastern part of Prakasam district confining to Musi-Gundlakamma sub-basins is heavily contaminated with nitrate and fluoride. Distinct water chemistry is noticed among each group of samples segregated based on concentration of these contaminants. The nitrate is as high as 594 mg/l and 57 % of the samples have it in toxic level as per BIS drinking water standards, so also the fluoride which has reached a maximum of 8.96 mq/l and 43 % of samples are not fit for human consumption. Nitrate contamination is high in shallow aquifers and granitic terrains, whereas fluoride is in excess concentration in deeper zones and meta-sediments among the tested wells, and 25 % of samples suffer from both NO3 ? and F? contamination. Na+ among cations and HCO3 ? among anions are the dominant species followed by Mg2+ and Cl?. The NO3 ?-rich groundwater is of Ca2+–Mg2+–HCO3 ?, Ca2+–Mg2+–Cl? and Na+–HCO3 ? type. The F?-rich groundwater is dominantly of Na+–HCO3 ? type and few are of Na+–SO4 2? type, whereas the safe waters (without any contaminants) are of Ca2+–Mg2+–HCO3 ?– and Na+–HCO3 ? types. High molecular percentage of Na+, Cl?, SO4 2? and K? in NO3 ? rich groundwater indicates simultaneous contribution of many elements through domestic sewerage and agriculture activity. It is further confirmed by analogous ratios of commonly associated ions viz NO3 ?:Cl?:SO4 2? and NO3 ?:K+:Cl? which are 22:56:22 and 42:10:48, respectively. The F? rich groundwater is unique by having higher content of Na+ (183 %) and HCO3 ? (28 %) than safe waters. The K+:F?:Ca2+ ratio of 10:5:85 and K+:F?: SO4 2? of 16:7:77 support lithological origin of F? facilitated by precipitation of CaCO3 which removes Ca2+ from solution. The high concentrations of Na+, CO3 ? and HCO3 ? in these waters act as catalyst allowing more fluorite to dissolve into the groundwater. The indices, ratios and scatter plots indicate that the NO3 ? rich groundwater has evolved through silicate weathering-anthropogenic activity-evapotranspiration processes, whereas F? rich groundwater attained its unique chemistry from mineral dissolution-water–rock interaction-ion exchange. Both the waters are subjected to external infusion of certain elements such as Na+, Cl?, NO3 ? which are further aggravated by evaporation processes leading to heavy accumulation of contaminants by raising the water density. Presence of NO3 ? rich samples within F? rich groundwater Group and vice versa authenticates the proposed evolution processes.  相似文献   

16.
Balram Ambade 《Natural Hazards》2014,70(2):1535-1552
In the present work, chemical characterization and sources of fog water contaminants in the most polluted area of central India, Raipur, and its surroundings are described. The fog water (n = 22) was collected during 2010–2011 from six sites. The physical (i.e., pH, fog amount, electrical conductivity and TDS) and chemical (i.e., F?, Cl?, NO3 ?, SO4 2?, NH4 +, Na+, K+, Mg2+, Ca2+, Al, Mn, Fe, Cu, Zn, Pb and Hg) parameters of the fog water were investigated. The effect of meteorology, i.e., temperature, humidity and wind speed, on the precipitation of the fog water contaminants is discussed. The cluster and factor analysis are used to apportion the sources of the contaminants in the fog water.  相似文献   

17.
Hydrogeochemical assessment of groundwater in Isfahan province, Iran   总被引：2，自引：2，他引：0  
Groundwater quality in five catchment areas in Isfahan province of Iran is assessed by measuring physicochemical parameters including major cation and anion compositions, pH, total dissolved solid, electrical conductivity and total hardness. For this purpose, 567 piezometric well samples were collected in October 2007. The abundance of major ions in four of the catchment areas including Gavkhuni, Ardestan, Salt lake and Central Iran desert basins is similar and follows Cl??>?SO4 2??>?Na+?>?HCO3 ??>?Ca2+?>?Mg2+?>?K+?>?CO3 2? trend, while in the fifth basin (Karoon), the trend changes into HCO3 ??>?Ca2+?>?Cl??>?SO4 2??>?Mg2+?>?Na+?>?K+?>CO3 2?. In general, four water facies are determined and it is shown that alkali elements and strong acids are dominating over alkaline earth and weak acids. Statistical analysis including Mann?CWhitney U test indicate that physicochemical parameters in three of the five investigated basins [Gavkhuni, Ardestan and Central Iran desert (CID)] are similar, while Karoon and salt lake basins display different characteristics. The result indicate that groundwater west of the province is suitable for irrigation, while in the central and eastern parts of the province the groundwater loses its quality for this purpose. It is concluded that mineral dissolution and evapotranspiration are the main processes that determine major ion compositions.  相似文献   

18.
In this study, the physicochemical parameters (Conductivity, pH, Cl?, HCO 3 ? , PO 4 3? , SO 4 2? , NO 3 ? , NO 2 ? , F?, TH, Ca2+, K+, Mg2+, Na+, and DS) were determined for 41 samples collected from fourteen places in Algeria. The temperature of the thermal water samples at collection sites varied from 26°C to 86°C. pH values varied from 6.5 to 8.5 (i.e., from slightly acidic to moderately alkaline); 90.24% of the samples exhibited relatively high salinity (DS?=?550–5,500 mg L?1). Total hardness measurements indicated these waters to be moderately hard. Forty-six percent of the samples are Na–Cl in character. The ratios Na+/Ca2+, Na+/Mg2+, and (Na+ + K+)/(Ca2+ + Mg2+) were high in 90.24% of the samples. This indicates the ion exchange process is important, which indicates that most of the Algerian thermal waters had developed over a long period at a depth sufficient to react with the rock. Statistical analyses of the physicochemical data gave positive correlation values, thereby enabling good interpretation of the results and revealing the composition of ions present in the thermal waters, as well as some information about their origin. The therapeutic properties associated with thermal waters encourage people at spas to drink the water they bathe in. Therefore, we examined the drinkability of these thermal waters. World Health Organization (WHO 1993) standards were used to evaluate the thermal water quality for drinking. With respect to hardness, the samples were classified as moderately hard (58.54% of the samples), very hard (36.58% of the samples), and soft (4.88% of the samples). The drinkability study shows that only 16 samples of the investigated waters were drinkable and thus could be consumed without special precaution.  相似文献   

19.
South China is one of the regions severely suffering from acid rain in the world.However,few systematic studies of rural precipitation chemistry have been performed in comparison with the extensive studies on their urban counterparts of this region.In order to characterize the current acid rain status and identify its possible sources in the rural area of South China,we analyzed precipitation collected event by event from a rural forested watershed in southern Anhui Province between March 2007 and February 2010.The results showed that the concentrations of major ions within precipitation in the studied rural area were significantly lower than those reported for the urban areas of the same latitude in China.Nevertheless,the precipitation acidity(with an average pH value of 4.49) and the frequency of acid rain(95%) were considerably high.The relatively high ratio of(SO42+ NO 3)/(Ca2+ +NH4+) was the main cause of acid rain in this rural area,as SO 2 and NO x were the main precursors of acid rain,while Ca2+ and NH4+acted as the dominant neutralizers to the acidity.Source identification indicated that Ca2+ and Mg2+ mainly were derived from alkaline dust,SO42,NO 3 and NH4+originated mainly from anthropogenic sources such as industrial and agricultural activities,most Na +,Cl,K + and some of Mg2+ were derived from the sea.The results suggested that the major ions within precipitation in the rural area of South China were related to the meso-scale and long-range transport of particles and aerosols in the air.  相似文献   

20.
A study was carried out in the Madurai district of Tamil Nadu, India to identify the hydrogeochemical processes using factor analysis as a predictive tool. It also focuses on characterizing the samples of these factors with respect to standard geochemical plots. In order to obtain a synoptic view of the statistics and the geochemical processes, a total of 53 groundwater samples are collected representing the entire district. The major ions were analyzed; the order of ion dominance are Ca2+?>?Na+?>?Mg2+?>?K+?=?Cl??>?HCO? 3?>?H4SiO? 4?>?NO? 3?>?SO2? 4?>?P3? 4. The samples are classified according to three factors. Factor 1 shows strong positive loadings of Cl?, Ca2+, Mg2+, and NO? 3 with 36.98 % of the total variance (TV); factor 2 accounts for 13.72 % of TV with high loadings of Na+, K+, and HCO? 3; and factor 3 shows strong positive loadings of PO3? 4 and SO2? 4 with TV of 13.1 %. In the Piper plot, few samples fall in the mix region as evidenced by the mixing proportion of two samples using AQUACHEM software. The results suggest that different hydrogeochemical processes, like weathering, ion exchange processes, and anthropogenic activities (like sewage infiltration and agriculture), has predominant impact in the study area. Thus, the study highlights the factor analysis technique as a predictive and effective tool for groundwater evolution.  相似文献   

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