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1.
Julien Nikiema Mario Schirmer Walter Gläßer Ronald Krieg 《Environmental Earth Sciences》2010,61(1):11-26
About 24 samples from hand-dug wells and boreholes were used to characterize concentrations of the main inorganic ions in
a laterite environment under semi-arid climatic conditions in Tikaré, northern Burkina Faso. It was found that the most represented
groundwater anion in groundwater was HCO3
− with average levels of 49.1 mg/L in the dry season and 33.5 mg/L in the rainy season. The most represented cation was Ca2+ with mean concentrations of 13.7 and 9.5 mg/L, respectively. The main processes, which influence the concentrations of these
ions, are evaporation (dry season), local enrichment of recharge water in some elements, ion exchange and fixation by clay
minerals (in case of K+). The best correlations were found between Ca2+ and Mg2+ (r = 0.95), Cl− and Na+ (r = 0.95), HCO3
− and Mg2+ (r = 0.89), HCO3
− and Ca2+ (r = 0.89), and between HCO3
− and Na+ (r = 0.80). In general, the quality of the groundwater from the different wells sampled for this study was good enough to serve
as drinking water. However, there were situations where the quality of water was polluted because of anthropogenic contaminants
(mainly NO3
−, K+, Cl−) from septic tanks and manure pits located in the vicinity of some sampled wells. In addition, application of fertilizers
also represents a potential anthropogenic contamination source with regard to SO4
2−, Ca2+, K+, Na+, and Mg2+. Considering the high concentrations of SO4
2−, Mg2+, Na+ and Ca2+ found in one borehole, the deeper, fractured aquifers were also likely to be enriched in these elements. In contrast, the
shallow aquifers are likely to be contaminated with Cl−, NO3
− and K+. Cl− and K+ seem to be locally present in recharge water as shown by their relative higher mean concentrations in the rainy season samples. 相似文献
2.
National scale evaluation of groundwater chemistry in Korea coastal aquifers: evidences of seawater intrusion 总被引:3,自引:2,他引:1
Youngyun Park Jin-Yong Lee Jeong-Hee Kim Sung-Ho Song 《Environmental Earth Sciences》2012,66(3):707-718
Pollution of groundwater by seawater intrusion poses a threat to sustainable agriculture in the coastal areas of Korea. Therefore, seawater intrusion monitoring stations were installed in eastern, western, and southern coastal areas and have been operated since 1998. In this study, groundwater chemistry data obtained from the seawater intrusion monitoring stations during the period from 2007 to 2009 were analyzed and evaluated. Groundwater was classified into fresh (<1,500 μS/cm), brackish (1,500–3,000 μS/cm), and saline (>3,000 μS/cm) according to EC levels. Among groundwater samples (n = 233), 56, 7, and 37% were classified as the fresh, brackish, and saline, respectively. The major dissolved components of the brackish and saline groundwaters were enriched compared with those of the fresh groundwater. The enrichment of Na+ and Cl− was especially noticeable due to seawater intrusion. Thus, the brackish and saline groundwaters were classified as Ca–Cl and Na–Cl types, while the fresh groundwater was classified as Na–HCO3 and Ca–HCO3 types. The groundwater included in the Na–Cl types indicated the effects of seawater mixing. Ca2+, Mg2+, Na+, K+, SO4 2−, and Br− showed good correlations with Cl− of over r = 0.624. Of these components, the strong correlations of Mg2+, SO4 2−, and Br− with Cl− (r ≥ 0.823) indicated a distinct mixing between fresh groundwater and seawater. The Ca/Cl and HCO3/Cl ratios of the groundwaters gradually decreased and approached those of seawater. The Mg/Cl, Na/Cl, K/Cl, SO4/Cl, and Br/Cl ratios of the groundwaters gradually decreased, and were similar to or lower than those of seawater, indicating that Mg2+, Na+, K+, SO4 2−, and Br−, as well as Cl− in the saline groundwater can be enriched by seawater mixing, while Ca2+ and HCO3 − are mainly released by weathering processes. The influence of seawater intrusion was evaluated using threshold values of Cl− and Br−, which were estimated as 80.5 and 0.54 mg/L, respectively. According to these criteria, 41–50% of the groundwaters were affected by seawater mixing. 相似文献
3.
This study was carried out to analyze groundwater quality in selected villages of Nalbari district, Assam, India, where groundwater
is the main source of drinking water. 40 groundwater samples collected from hand pumps and analyzed for pH, EC, TDS, Ca2+, Mg2+, Na+, K+, HCO3
−, SO4
2−, Cl− and F−. Chemical analysis of the groundwater showed that mean concentration of cations in (mg/L) is in the order Ca2+ > Mg2+ > Na+ > K+ while for anions it is HCO3
− > Cl− > SO4
2− > F−. Fluoride concentration was recorded in the range of 0.02–1.56 mg/L. As per the desirable and maximum permissible limits
for fluoride in drinking water recommended by WHO and by Bureau of Indian Standards (BIS), which is 1.5 mg/L, the groundwater
of about 97% of the samples were found to be suitable for drinking purpose. The suitability of the groundwater for irrigation
purpose was investigated by some determining factors such as sodium adsorption ratio, soluble sodium percentage, Kelly’s ratio
and electrical conductivity. The value of the sodium absorption ratio and electrical conductivity of the groundwater samples
were plotted in the US Salinity laboratory diagram for irrigation water. Most of the groundwater samples fall in the field
of C2S1 and C3S1 indicating medium to high salinity and low sodium water, which can be used for irrigation on almost all types
of soil with little doubt of exchangeable sodium. The hydrochemical facies shows that the groundwater is Ca-HCO3 type. 相似文献
4.
Mohsen Jalali 《Environmental Geology》2005,47(6):763-772
Hydrochemical investigations were carried out in Bahar area, Hamadan, western Iran, to assess the chemical composition of groundwater. The area falls in a semi-arid type of climate. In this area, groundwater has been exploited over the past century mainly for irrigation and water supply. A total of 135 representative groundwater samples were collected from different wells to monitor the water chemistry of various ions. Chemical analysis of the groundwater shows that the mean concentration of the cations is of the order Ca2+>Mg 2+>Na+>K+, while that for anions is SO42–>HCO3–>Cl–>NO3–. Statistical analyses indicate positive correlation between the following pairs of parameters Cl– and Mg 2+ (r=0.71), Cl– and Na+ (r=0.76), HCO3– and Na+ (r=0.56), SO42– and Mg2+ (r=0.76), SO42– and Na+ (r=0.69). Water presents a large spatial variability of the chemical facies (Ca-HCO3, Ca-SO4, Mg-HCO3, Mg-SO4, Na-HCO3) which is in relation to their interaction with the geological formations of the basin (carbonates, dolomite and various silicates) and evaporation. The hydrochemical types Ca-HCO3 and Ca-SO4 dominate the largest part of the studied area. The dissolution of halite, calcite, dolomite, and gypsum explains part of the contained Na +, Ca2+, Mg2+, Cl–, SO42– and HCO3–, but other processes, such as cation exchange and weathering of aluminosilicates also contribute to the water composition. 相似文献
5.
Hydrochemical characteristics of groundwater in the Zhangye Basin, Northwestern China 总被引:3,自引:0,他引:3
The Zhangye Basin, located in arid northwest China, is an important agricultural and industrial center. In recent years rapid
development has created an increased demand for water, which is increasingly being fulfilled by groundwater abstraction. Detailed
knowledge of the geochemical evolution of groundwater and water quality can enhance understanding of the hydrochemical system,
promoting sustainable development and effective management of groundwater resources. To this end, a hydrochemical investigation
was conducted in the Zhangye Basin. Types of shallow groundwater in the Zhangye Basin were found to be HCO3
−, HCO3
−–SO4
2−, SO4
2−–HCO3
−, SO4
2−–Cl−, Cl−–SO4
2− and Cl− . The deep aquifer groundwater type was found to be HCO3−–SO42− throughout the entire area. Ionic ratio and saturation index calculations suggest that silicate rock weathering and evaporation
deposition are the main processes that determine the ionic composition in the study area. The suitability of the groundwater
for irrigation was assessed based on the US Salinity Laboratory salinity classification and the Wilcox diagram. In the study
area, the compositions of the stable isotopes δ18O and δD in groundwater samples were found to range from −4.00 to −9.28‰ and from −34.0 to −65.0‰, respectively. These values
indicate that precipitation is the main recharge source for the groundwater system; some local values indicate high levels
of evaporation. Tritium analysis was used to estimate the ages of the different groundwaters; the tritium values of the groundwater
samples varied from 3.13 to 36.62 TU. The age of the groundwater at depths of less than 30 m is about 5–10 years. The age
of the groundwater at depths of 30–50 m is about 10–23 years. The age of the groundwater at depths of 50–100 m is about 12–29 years.
For groundwater samples at depths of greater than 100 m, the renewal time is about 40 years. 相似文献
6.
Hydrochemical characteristics and quality assessment of shallow groundwater in a coastal area of Southwest Bangladesh 总被引:4,自引:3,他引:1
In this study, the hydrochemical characteristics of shallow groundwater in a coastal region (Khulna) of southwest Bangladesh
have been evaluated based on different indices for drinking and irrigation uses. Water samples were collected from 26 boreholes
and analyzed for major cations and anions. Other physico-chemical parameters like pH, electrical conductivity (EC), and total
dissolved solids were also measured. Most groundwater is slightly alkaline and largely varies in chemical composition, e.g.
EC ranges from 962 to 9,370 μs/cm. The abundance of the major ions is as follows: Na+ > Ca2+ > Mg2+ > K+ = Cl− > HCO3
− > SO4
2− > NO3
−. Interpretation of analytical data shows two major hydrochemical facies (Na+–K+–Cl−–SO4
2− and Na+–K+–HCO3
−) in the study area. Salinity, total hardness, and sodium percentage (Na%) indicate that most of the groundwater samples are
not suitable for irrigation as well as for domestic purposes and far from drinking water standard. Results suggest that the
brackish nature in most of the groundwaters is due to the seawater influence and hydrogeochemical processes. 相似文献
7.
Mohsen Jalali 《Environmental Geology》2009,56(7):1479-1488
This study was conducted to evaluate factors regulating groundwater quality in an area with agriculture as main use. Thirty
groundwater samples have been collected from Razan area (Hamadan, Iran) for hydrochemical investigations to understand the
sources of dissolved ions and assess the chemical quality of the groundwater. The chemical compositions of the groundwater
are dominated by Na+, Ca2+, HCO3
−, Cl− and SO4
2−, which have been derived largely from natural chemical weathering of carbonate, gypsum and anthropogenic activities of fertilizer’s
source. The production of SO4
2− has multiple origins, mainly from dissolution of sulphate minerals, oxidation of sulphide minerals and anthropogenic sources.
The major anthropogenic components in the groundwater include Na+, Cl−, SO4
2− and NO3
−, with Cl− and NO3
− being the main contributors to groundwater pollution in Razan area. 相似文献
8.
Influence of hydrogeochemical processes on temporal changes in groundwater quality in a part of Nalgonda district, Andhra Pradesh, India 总被引:4,自引:3,他引:1
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 SO4
2− were analyzed using ion chromatograph. CO3
− and HCO3
− concentration 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
− > SO4
2− > 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. 相似文献
9.
An integrated geological, geoelectrical and hydrochemical investigation of shallow groundwater occurrence in the Ibadan area,
southwestern Nigeria, is presented. The primary objective was to characterise the groundwater in a typical low-latitude environment
underlain by Precambrian crystalline basement complex rocks. The dominant rocks comprise suites of gneisses and quartzites.
Chemical analyses of the groundwater show that the mean concentration of the cations is in the order Na>Ca>Mg>K while that
for the anions is Cl>HCO3>NO3>SO4. Statistical analyses, using the product-moment coefficient of correlation, indicate positive correlations between the following
pairs of parameters: TDS and conductivity (r=0.96); Na++Mg2+ and Cl– (r=0.95); Na++K+ and Ca2+ (r=0.43); Na++K+ and HCO3
– (r=0.17); Ca2+ and Mg2+ (r=0.74); Ca2+ and HCO3
– (r=0.33); Ca2++Mg2+ and HCO3
– (r=0.31) and pH and HCO3
– (r=0.54). A very weak negative correlation was recorded between pH and Cl–, with r=–0.003. Five groundwater groups have been identified, namely, (1) the Na-Cl, Na-Ca-Cl, Na-Ca-(Mg)-Cl; (2) the Ca-(Mg)-Na-HCO3-Cl, Na-Ca-HCO3-Cl, and Ca-HCO3-Cl; (3) the Ca-(Mg)-Na-HCO3, Ca-Na-HCO3; (4) Ca-Na-Cl-(SO4)-HCO3 and (5) the Ca-(Mg)-Na-SO4-HCO3. The different groups reflect the diversity of bedrock types and consequently also of the products of weathering. Most of
the water sampled is unfit for drinking on account of the high NO3
– content. It can, however, be used for irrigation purposes as the sodium hazard is low while the salinity hazard ranges from
low to medium. Resistivity soundings indicate the presence of a thick weathering profile, which could be up to 60 m. Such
sites should be the target for any long-term and sustainable groundwater development in the area.
Received: 15 April 1998 · Accepted: 4 July 1998 相似文献
10.
The Markanda river basin occupying an area of about 1547 km2 is a part of the alluvial deposits of the Indo- Gangetic plain near the Himalayan foothills in the northwest India. The region
is associated with active agricultural activities and makes significant contribution to the country’s agricultural products.
Assessment of groundwater quality for irrigation use and hydrochemical evolution of groundwater has been studied. Hydrochemical
analysis has been carried out based on concentrations of Ca2+, Mg2+, Na+, K+, Cl−, SO4
2−, CO3
2− and HCO3
−. Sodium adsorption ratio (SAR), percent sodium (%Na), permeability index (PI) and Trilinear diagram have been studied to
evaluate suitability of irrigation use. Hydrochemical evolution has been analyzed based on the Chebotarev sequence and expanded
Durov diagram. SAR, %Na and PI results indicate that the groundwater in the basin is suitable for irrigation use. Analysis
on Trilinear diagram reveals that hydrochemical facies are dominated by HCO3
−- Ca2+- Mg2+ facies indicating that the groundwater is associated with recharge waters percolating through sandstone and limestone rocks
which are exposed in the northern part of the basin. Studies based on Chebotarev anion sequence and expanded Durov diagram
indicate that the evolution of groundwater belongs to initial to intermediate stage indicating fresh water quality. Thus,
the present work reveals that groundwater in the Markanda basin is of good quality and is suitable for all uses including
interbasin water transfer in the region. 相似文献
11.
Hydrogeochemical investigations are carried out in the different blocks of Burdwan district, West Bengal, India in order to
assess its suitability for drinking as well as irrigation water purpose. Altogether 49 representative groundwater samples
are collected from bore wells and the water chemistry of various ions viz. Ca2+, Mg2+, Na+, K+, CO32−, HCO3−, Cl−, SO42− and NO3− are carried out. The chemical relationships in Piper and Gibbs diagram suggest that the groundwater mainly belongs to alkali
type and Cl− group and are controlled by rock dominance. A comparison of groundwater quality in relation to drinking water quality standards
proves that most of the water samples are suitable for drinking water purpose whereas groundwater in some areas of the district
has high salinity and high sodium adsorption ratio (SAR), indicating unsuitability for irrigation water and needs adequate
drainage. 相似文献
12.
Environmental geochemistry and quality assessment of surface and subsurface water of Mahi River basin, western India 总被引:4,自引:3,他引:1
The hydrogeochemical study of surface and subsurface water of Mahi River basin was undertaken to assess the major ion chemistry,
solute acquisition processes and water quality in relation to domestic and irrigation uses. The analytical results show the
mildly acidic to alkaline nature of water and dominance of Na+ and Ca2+ in cationic and HCO3
− and Cl− in anionic composition. In general, alkaline-earth elements (Ca2+ + Mg2+) exceed alkalis (Na+ + K+) and weak acids (HCO3
−) dominate over strong acids (SO4
2+ + Cl−) in majority of the surface and groundwater samples. Ca2+–Mg2+–HCO3
− is the dominant hydrochemical facies both in surface and groundwater of the area. The weathering of rock-forming minerals
mainly controlled the solute acquisition process with secondary contribution from marine and anthropogenic sources. The higher
concentration of sodium and dissolved silica, high equivalent ratios of (Na+ + K+/TZ+), (Na+ + K+/Cl−) and low ratio of (Ca2+ + Mg2+)/(Na+ + K+) suggest that the chemical composition of the water is largely controlled by silicate weathering with limited contribution
from carbonate weathering and marine and anthropogenic sources. Kaolinite is the possible mineral that is in equilibrium with
the water, implying that the chemistry of river water favors kaolinite formation. Assessment of water samples for drinking
purposes suggests that the majority of the water samples are suitable for drinking. At some sites concentrations of TDS, TH,
F−, NO3
− and Fe are exceeding the desirable limit of drinking. However, these parameters are well within the maximum permissible limit
except for some cases. To assess the suitability for irrigation, parameters like SAR, RSC and %Na were calculated. In general,
both surface and groundwater is of good to suitable category for irrigation uses except at some sites where high values of
salinity, %Na and RSC restrict its uses. 相似文献
13.
Hydrochemical investigations were carried out in Damagh area, Hamadan, western Iran, to assess chemical composition of groundwater.
Forty representative groundwater samples were collected from different wells to monitor the water chemistry of various ions.
Chemical analysis of the groundwater showed that the mean concentration of the cations is in the order Na+ > Ca2+ > Mg2+ > K+, while that for anions was HCO3− > Cl− > SO42 − > NO3−. All of the investigated groundwaters present two different chemical facies (Ca–HCO3 and Na–HCO3) which is in relation with their interaction with the geological formations of the basin, cation exchange between groundwater
and clay minerals and anthropogenic activities. The principal component analysis (PCA) performed on groundwater identified
three principal components controlling their variability in groundwater. Electrical conductivity, Mg2+, Na+, SO42−, and Cl− content were associated in the same component (PC1) (salinity), determined principally by anthropogenic activities. The pH,
CO32 −, HCO3−, and Ca2+ (PC2) content were related to the geogenic factor. Finally, the NO3−, Cl− and K+ (PC3) were controlled by anthropogenic activity as a consequence of inorganic fertilizers. 相似文献
14.
Mirza A. T. M. Tanvir Rahman Ratan Kumar Majumder Syed Hafizur Rahman Md. Abdul Halim 《Environmental Earth Sciences》2011,63(2):363-373
Twenty groundwater samples were collected from two different areas in Satkhira Sadar Upazila to identify the source of salinity
in deep groundwater aquifer. Most of the analyzed groundwater is of Na–Cl–HCO3 type water. The trends of anion and cation are Cl− > HCO3
− > NO3
− > SO4
2− and Na+ > Ca2+ > Mg2+ > K+, respectively. Groundwater chemistry in the study area is mainly governed by rock dissolution and ion exchange. The dissolved
minerals in groundwater mainly come from silicate weathering. The salinity of groundwater samples varies from ~1 to ~5%, and
its source is possibly the paleo-brackish water which may be entrapped during past geologic periods. 相似文献
15.
M. A. Halim R. K. Majumder S. A. Nessa K. Oda Y. Hiroshiro B. B. Saha S. M. Hassain Sk. A. Latif M. A. Islam K. Jinno 《Environmental Geology》2009,58(1):73-84
An integrated study has been carried out to elucidate the distribution and occurrence of arsenic in selected groundwater samples
in the area of Sherajdikhan, Bangladesh. Arsenic and other parameters (T, pH, EC, Na+, K+, Ca2+, Mg2+, Cl−, NO3
−, SO4
2−, HCO3
−, PO4
3−, Fe, Mn and DOC) have been measured in groundwater samples collected from shallow/deep tube wells at different depths. Hydrogeochemical
data suggest that the groundwaters are generally Ca–Mg–HCO3 and Mg–Ca–HCO3 types with bicarbonate (HCO3
−) as the dominant anion, though the other type of water has also been observed. Dissolved arsenic in groundwater ranged from
0.006 to 0.461 mg/l, with 69% groundwater samples exceeded the Bangladesh limit for safe drinking water (0.05 mg/l). Correlation
and principal component analysis have been performed to find out possible relationships among the examined parameters in groundwater.
Low concentrations of NO3
− and SO4
2−, and high concentrations of DOC, HCO3
− and PO4
3− indicate the reducing condition of subsurface aquifer where sediments are deposited with abundant organic matter. Distinct
relationship of As with Fe and Mn, and strong correlation with DOC suggests that the biodegradation of organic matter along
with reductive dissolution of Fe–Mn oxyhydroxides has being considered the dominant process to release As in the aquifers
studied herein. 相似文献
16.
Geochemistry of groundwater,Markandeya River Basin,Belgaum district,Karnataka State,India 总被引:1,自引:0,他引:1
The Markandeya River Basin stretches geographically from 15o56′ to 16o08′ N latitude and 74o37′ to 74o58′ E longitude, positioned in the midst of Belgaum district, in the northern part of Karnataka. The groundwater quality of 54 pre-monsoon samples in the Markandeya River Basin was evaluated for its suitability for drinking and irrigation purposes by estimating pH, EC, TDS, hardness and alkalinity besides major cations (Na+, K+, Ca2+, Mg2+) and anions (HCO3–, Cl–, SO42–, PO43-, F-, NO3–), boron, SAR, % Na, RSC, RSBC, chlorinity index, SSP, non-carbonate hardness, Potential Salinity, Permeability Index, Kelley’s ratio, Magnesium hazard and Index of Base Exchange. Negative Index of Base Exchange indicates the chloro-alkaline disequilibrium in the study area and the majority of water samples fall in the rock dominance field based on Gibbs’ ratio. Permeability indices of classes I and II suggest suitability of groundwater for irrigation. Based on Cl, SO4, HCO3 concentrations, water samples can be classified as normal chloride (96.3%) and normal sulfate (94.4%) and normal bicarbonate (44.4%) water types. 相似文献
17.
Spatio-temporal characterization of the Pliocene aquifer conditions in Wadi El-Natrun area,Egypt 总被引:3,自引:1,他引:2
Wadi El-Natrun area has recently undergone extensive urban and agricultural expansion. Due to the absence of natural surface
irrigation supplies, the only source of water in the area is the Pliocene groundwater aquifer. As a result, secondary salinization
from increased abstractions is the major threat to the groundwater aquifer. There is a dire need for efficient strategies
to ensure long-term sustainability of the area’s productive agriculture. These strategies should be based on scientific spatio-temporal
monitoring and analysis of the groundwater conditions that is also lacking. To capture the spatio-temporal variability in
groundwater conditions, field measurements of total dissolved solids, electrical conductivity, pH, temperature, and water
level as well as lab-based ionic composition were performed on 47 groundwater samples collected during 2006 and 2007. Determinations
of the hydrochemical characteristics, water types, salt assemblages, and the sodium adsorption ratio were carried out on the
samples. Reference data sets recorded in 1973 and 1997 were available for the area and were used to monitor the changes occurred
in these periods. Geographic information system (GIS) was appraised for mapping and for integrated analysis of the different
layers. Remotely sensed change detection techniques were applied to the Landsat TM and the ETM + imageries and used to highlight
the extensive reclamation and urbanization and to find key trends for the alterations in the groundwater conditions and their
spatial association with land covers. Results revealed a topographic depression-induced flow pattern, predominance of leaching
and dissolution processes, the presence of saline lakes, over-pumping from the Pliocene aquifer, and temporal changes in land
uses are the main factors combined to control the spatio-temporal variability in the groundwater. Results also clarified the
presence of two: northwestern and southeastern zones that varied distinctively in their hydrodynamic and hydrochemical characteristics.
The northwestern zone showed an average water level decline of 15 m, the water of which is brackish (av. 2,037 mg/l) with dominant Na+, Cl− and SO4
2− ions. The groundwater of this zone is characterized by high to very high salinity hazard and high to very high alkali hazard
and is not recommended for irrigation on soils with poor drainage and without proper management for salinity control. The
southeastern zone showed water level decline less than 2 m, the water of which is fresh (av. 424 mg/l) with major Na+, HCO3
−, Cl−, and SO4
2− ions, and quality suitable for irrigation with medium to high salinity and low to medium alkali hazards. The article represents
the first step towards an integrated management of Wadi El-Natrun groundwater resources within a GIS framework. 相似文献
18.
Characterization and appraisal of facets influencing geochemistry of groundwater in the Kulpawn sub-basin of the White Volta Basin, Ghana 总被引:1,自引:0,他引:1
Groundwater composition in the Kulpawn basin is largely controlled by aluminosilicates dissolution and cation exchange resulting
in mainly Ca-Mg-HCO3 and NaHCO3 water types. Principal component analysis, Piper graphical classification, and stable isotope (18O and 2H) of groundwater and surface-water samples were used to delineate geochemical processes and groundwater facies. The groundwater
is mildly acid to neutral and low in conductivity. Chemical constituents except HCO3
− and SiO2 have low concentration. No cation shows clear majority, however, the order of relative abundance is Na+ > Ca2+ > Mg2+ > K+. HCO3
− is the predominant anion and the order of abundance is HCO3
− > NO3
− > SO4
2− > Cl−. SiO2 concentration is high compared with the major cations. Dissolution of plagioclase, pyroxene and biotite and cation exchange
are responsible for groundwater composition. Isotopic data suggest integrative, smooth and rapid recharge from meteoric origin.
The groundwater quality is generally good for domestic usage; however, 18 and 47% of boreholes respectively have NO3
− and F− levels outside WHO recommended limits suggesting potential physiological problems in some localities. The groundwater has
low sodium absorption ratio and low to moderate salinity hazard but significant magnesium hazard partially limiting its use
for irrigation. 相似文献
19.
Anwar Zahid M. Qumrul Hassan K.-D. Balke Matthias Flegr David W. Clark 《Environmental Geology》2008,54(6):1247-1260
Dissolved major ions and important heavy metals including total arsenic and iron were measured in groundwater from shallow
(25–33 m) and deep (191–318 m) tube-wells in southeastern Bangladesh. These analyses are intended to help describe geochemical
processes active in the aquifers and the source and release mechanism of arsenic in sediments for the Meghna Floodplain aquifer.
The elevated Cl− and higher proportions of Na+ relative to Ca2+, Mg2+, and K+ in groundwater suggest the influence by a source of Na+ and Cl−. Use of chemical fertilizers may cause higher concentrations of NH4+ and PO43− in shallow well samples. In general, most ions are positively correlated with Cl−, with Na+ showing an especially strong correlation with Cl−, indicating that these ions are derived from the same source of saline waters. The relationship between Cl−/HCO3− ratios and Cl− also shows mixing of fresh groundwater and seawater. Concentrations of dissolved HCO3− reflect the degree of water–rock interaction in groundwater systems and integrated microbial degradation of organic matter.
Mn and Fe-oxyhydroxides are prominent in the clayey subsurface sediment and well known to be strong adsorbents of heavy metals
including arsenic. All five shallow well samples had high arsenic concentration that exceeded WHO recommended limit for drinking
water. Very low concentrations of SO42− and NO3− and high concentrations of dissolved Fe and PO43− and NH4+ ions support the reducing condition of subsurface aquifer. Arsenic concentrations demonstrate negative co-relation with the
concentrations of SO42− and NO3− but correlate weakly with Mo, Fe concentrations and positively with those of P, PO43− and NH4+ ions. 相似文献
20.
Environmental geochemistry and quality assessment of mine water of Jharia coalfield,India 总被引:1,自引:0,他引:1
Abhay Kumar Singh M. K. Mahato B. Neogi B. K. Tewary A. Sinha 《Environmental Earth Sciences》2012,65(1):49-65
A long mining history and unscientific exploitation of Jharia coalfield caused many environmental problems including water
resource depletion and contamination. A geochemical study of mine water in the Jharia coalfield has been undertaken to assess
its quality and suitability for domestic, industrial and irrigation uses. For this purpose, 92 mine water samples collected
from different mining areas of Jharia coalfield were analysed for pH, electrical conductivity (EC), major cations (Ca2+, Mg2+, Na+, K+), anions (F−, Cl−, HCO3
−, SO4
2−, NO3
−), dissolved silica (H4SiO4) and trace metals. The pH of the analysed mine water samples varied from 6.2 to 8.6, indicating mildly acidic to alkaline
nature. Concentration of TDS varied from 437 to 1,593 mg L−1 and spatial differences in TDS values reflect the variation in lithology, surface activities and hydrological regime prevailing
in the region. SO4
2− and HCO3
− are dominant in the anion and Mg2+ and Ca2+ in the cation chemistry of mine water. High concentrations of SO4
2− in the mine water of the area are attributed to the oxidative weathering of pyrites. Ca–Mg–SO4 and Ca–Mg–HCO3 are the dominant hydrochemical facies. The drinking water quality assessment indicates that number of mine water samples
have high TDS, total hardness and SO4
2− concentrations and needs treatment before its utilization. Concentrations of some trace metals (Fe, Mn, Ni, Pb) were also
found to be above the desirable levels recommended for drinking water. The mine water is good to permissible quality and suitable
for irrigation in most cases. However, higher salinity, residual sodium carbonate and Mg-ratio restrict its suitability for
irrigation at some sites. 相似文献