Assessment of groundwater quality and its suitability for drinking and agricultural uses in arid environment

Groundwater quality in Ma’an area was evaluated for its suitability for drinking and agricultural uses by determining the main physical and chemical properties during a 1 year survey study (August 2009 to August 2010). Several samples were collected from ten different wells and analysed for temperature, pH, conductivity, total dissolved solids, total hardness, major cations (Ca²⁺, Mg²⁺, Na⁺ and K⁺), major anions (HCO₃ ^?, Cl^?, NO₃ ^?, SO₄ ^2?, F^? and Br^?) and trace metals (Fe²⁺, Al³⁺, Mn²⁺, Cu²⁺, Zn²⁺, Pb²⁺ and Cd²⁺). The general chemistry of water samples was typically of alkaline earth waters with prevailing bicarbonate chloride. The results showed great variations among the analyzed samples with respect to their physical and chemical parameters. However, most values were below the maximum permissible levels recommended by Jordanian and WHO drinking water standards. The quality assessment shows that in general, the GW in the study area is not entirely fit for direct drinking with respect to EC, and Pb²⁺. According to the residual sodium carbonate and sodium adsorption ratio, the water in the studied wells can be used for irrigational purposes.     

Fifty-year variations in water ionic composition in small tributaries of the Southern Baikal

Concentrations of major ions in surface waters of the rivers of Khara-Murin and Snezhnaya are compared based on data of many-year observations carried out in the 1950s and 2000s. The concentrations of HCO ₃ ^? , Cl^?, Ca²⁺, Mg²⁺, Na⁺ + K⁺ are shown to be stable. A considerable increase in SO ₄ ^?2 concentration was revealed.     

Water and nutrient fluxes in a cool temperate rainforest at the Cordillera de la Costa in southern Chile

Water and nutrient fluxes were studied during a 12-month period in an alerce (Fitzroya cupressoides) forest, located in a remote site at the Cordillera de la Costa (40°05′S) in southern Chile. Measurements of precipitation, throughfall, stemflow, effective precipitation, soil infiltration and stream flow were carried out in an experimental, small watershed. Simultaneously, monthly water samples were collected to determine the concentrations and transport of organic-N, NO₃-N, total-P, K⁺, Ca²⁺, Na⁺ and Mg²⁺ in all levels of forest. Concentration of organic-N, NO₃-N, total-P and K⁺ showed a clear pattern of enrichment in the throughfall, stemflow, effective precipitation and soil infiltration. For Ca²⁺ and Mg²⁺, enrichment was observed in the effective precipitation, soil infiltration and stream flow. Annual transport of K⁺, Na⁺, Ca²⁺ and Mg²⁺ showed that the amounts exported from the forest via stream flow (K⁺=0·95, Na⁺=32·44, Ca²⁺=8·76 and Mg²⁺=7·16 kg ha⁻¹ yr⁻¹) are less than the inputs via precipitation (K⁺=6·39, Na⁺=40·99, Ca²⁺=15·13 and Mg²⁺=7·61 kg ha⁻¹ yr⁻¹). The amounts of organic-N and NO₃-N exported via stream flow (organic-N=1·04 and No₃-N=3·06 kg ha⁻¹ yr⁻¹) were relatively small; however, they represented greater amounts than the inputs via precipitation (organic-N=0·74 and NO₃-N=0·97 kg ha⁻¹ yr⁻¹), because of the great contribution of this element in the superficial soil horizon, where the processes of decomposition of organic material, mineralization and immobilization of the nutrients occurs. © 1998 John Wiley & Sons, Ltd.     

柴达本盆地沙下盐湖的卤水化学及矿物沉积特征——以察尔汗盐湖区北部外围地带为例

对柴达木盆地察尔汗盐湖区外围沙下盐湖的卤水及沉积进行了综合研究。沙下盐湖卤水化学组成与地表径流和开放性盐湖卤水之间存在明显的差异性,具有高Na⁺+Cl^-、低Mg²⁺+Ca²⁺+SO₄^2-、贫K⁺+CO₃^2-+HCO₃^-等特征。沙下盐湖析盐层位含有新生矿物并夹带碎屑矿物,其盐类矿物组合为:石盐+羟氯镁铝石+光卤石。25℃等温蒸发相图表明,其卤水演化方向往光卤石析出区迁移,在穿越上覆盖层通道中卤水发生的物理化学反应与独特的沉积特征,可以作为继续寻找沙下盐湖的指导。     

Wildfire effects on extractable elements in ash from a Pinus pinaster forest in Portugal

The aim of this work is to study the effects of a wildfire on water‐extractable elements in ash from a Pinus pinaster forest located in Portugal. The pH, electrical conductivity (EC), calcium (Ca²⁺), magnesium (Mg²⁺), sodium (Na⁺), potassium (K⁺), sodium and potassium adsorption ratio (SPAR), aluminium (Al³⁺), manganese (Mn²⁺), iron (Fe²⁺), zinc (Zn²⁺), sulphur (S), silica (Si) and phosphorous (P) were analysed in ash sampled from a sloped area burned in a wildfire and from litter from a contiguous unburned area, with similar morphological conditions. The results showed that ash leachates had higher pH and EC, and were significantly richer in water‐extractable Ca²⁺, Mg²⁺, Na⁺, K⁺, SPAR, S and Si and significantly poorer in water‐extractable Al³⁺, Fe²⁺, Mn²⁺ and Zn²⁺ than litter solutions. No significant differences were observed in water‐extractable P. The fire changed the ash solute chemistry compared with the unburned litter and increased the sample variability of nutrient distribution with potential implications for plant recovery. Copyright © 2013 John Wiley & Sons, Ltd.     

The distribution of solute processes on an acid hillslope and the delivery of solutes to a stream: I. Exchangeable bases

This paper aims to identify the spatial distribution of exchangeable base cations in soils on an acid hillslope and to investigate possible cation release processes from slope soils to the stream. The basic assumption underlying this research is that the amount of exchangeable cations in soils reflects the nutrient stores and cation leaching processes across the slope where vegetation and parent materials are similar. The distribution of exchangeable Ca²⁺, Mg²⁺, K⁺ and Na⁺ has been investigated on a three-dimensional hillslope on the Quantock Hills, Somerset, UK. A two-way ANOVA shows that soil depth is predominant in explaining the total variance of exchangeable bases, despite the steep slope gradient and clear podzolic catena development. Major nutrient base cations, such as Ca²⁺, Mg²⁺ and K⁺, display homogeneous topsoil storage right across the slope. This spatial pattern may indicate that the spatial distribution of major nutrient cations is tightly controlled by the soil–vegetation system in nutrient-poor heathland environments. Na⁺ is an exception to this vegetation-controlled spatial distribution, because of its small involvement in the soil–vegetation and soil exchangeable systems. In subsurface soils, cations liberated from the soil–vegetation system are subject to redistribution over the slope according to the hydrological flowpaths operating on the slope, with some eventually released into the stream. The saturated wedge developed at the base of the slope plays a key role in the storage and release processes of base cations from slope soils to the stream. Ca²⁺, Mg²⁺ and Na⁺ carried by throughflow are stored in the saturated wedge and gradually released into the stream at times of high flow. K⁺, however, shows an apparently different spatial behaviour, being deficient in the saturated wedge. Copyright © 1999 John Wiley & Sons, Ltd.     

粤东五华河流域的化学风化与CO2吸收

基于对粤东五华河干流和支流水体的物理、化学组成测试数据,应用质量平衡法和相关分析法探讨湿热山地丘陵地区岩石化学风化过程对大气CO₂的吸收.结果表明:五华河水体的总溶解性固体含量(77.11 mg/L)接近于世界河流的平均值(65 mg/L);离子组成以Ca²⁺、Na⁺和HCO₃^-为主,可溶性Si次之.五华河流域化学径流组成主要源自硅酸盐矿物化学风化过程的贡献,碳酸盐矿物的贡献较少;大气和土壤CO₂是流域内岩石化学风化的主要侵蚀介质.与同一气候带其他河流相比较,五华河流域岩石化学风化过程对大气CO₂的吸收通量(2.14×105mol/(km²·a))较低,这主要是由于流域内缺乏碳酸盐岩所导致.     

Hydrogeochemical balance of forest umbrisol profiles (‘Sierra de Gata’, central western Spain)

Three techniques for obtaining soil water solutions (gravitational and matrical waters extracted using both in situ tension lysimeters and in vitro pressure chambers) and their later chemical analysis were performed in order to know the evolution of the soil‐solution composition when water moves down through the soil, from the Ah soil horizon to the BwC‐ or C‐horizons of forest soils located in western Spain. Additionally, ion concentrations and water volumes of input waters to soil (canopy washout) and exported waters (drainage solutions from C‐horizons) were determined to establish the net balance of solutes in order to determine the rates of leaching or retention of ions. A generalized process of sorption or retention of most components (even Cl^?) was observed, from the soil surface to the C‐horizon, in both gravitational and matrical waters, with H₄SiO₄, Mn²⁺, Na⁺, and SO₄^2? being the net exported components from the soil through the groundwater. These results enhance the role of the recycling effect in these forest soils. The net percentages of elements retained in these forest soils, considering the inputs and the outputs balance, were 68% K⁺, 85% Ca²⁺, 58% Mg²⁺, 7% Al³⁺, 5% Fe³⁺, 34% Zn²⁺, 57% Cl^?, and 20% NO₃^?, and about 75% of dissolved organic carbon was mineralized. Copyright © 2007 John Wiley & Sons, Ltd.     

Soluble salt deposit in the Nihewan beds and its environmental significance

Observation and experimental analysis of soluble salt deposit along four profiles across the strata deposited in Nihewan paleolake basin enabled us to recognize the nature and evolution stages of the Nihewan paleolake and its significance in stratigraphical division and pa-leo-environmental reconstruction. The Nihewan paleolake was at least a weak-saline to semi-saline lake and represents an intracontinental lake in the semi-arid region. The lower member of sedimentary strata in the paleolake contains gypsum layer and gypsum lamellae. Soluble salt is mainly composed of SO ₄ ^2- and Ca²⁺ ions, representing a trend of the paleolake evolving into a stage of sulfate lake. The upper member of the strata has predominantly Cl^-, K⁺, and Na⁺ ions in soluble salt, indicating a starting development of the paleolake to chlorite lake, but no salt rock was deposited, indicating a drying trend of the area.     

Switch in chemical weathering caused by the mass balance variability in a Himalayan glacierized basin: a case of Chhota Shigri Glacier

Long-term data (2003–2015) on meltwater chemistry, mass balance and discharge of a benchmark glacier (Chhota Shigri Glacier, India) were studied to determine any association between these variables. To infer the factors governing the alteration of chemical weathering processes in glacierized basins, multi-annual records of the hydrochemical indices (Ca²⁺+Mg²⁺/Na⁺+K⁺) and the C-ratio were also examined. A succession of negative mass balance years has resulted in a decline in solute concentrations in the runoff, as discharge has increased. The (Ca²⁺+Mg²⁺/Na⁺+K⁺) and C-ratio are highest during periods of negative annual mass balance, when the spatial extent of the channelized drainage system increases. Conversely, these ratios are lowest in positive mass balance years, when the spatial extent of the channelized drainage system decreases, and chemical weathering in the distributed drainage system becomes more dominant. This paper is the first to show the inter-annual linkages between meltwater chemistry, mass balance and discharge for a valley glacier.     

Spatial and temporal variability of groundwater quality of an Algerian aquifer: the case of Soummam Wadi

ABSTRACT

Five-year monitoring of physicochemical parameters was performed with two campaigns in low and high water periods of the Lower Soummam catchment. Data from 18 wells were processed by multivariate statistical tools in order to identify the principal factors influencing groundwater chemistry. Two matrices of 14 and 8 physicochemical parameters with 18 groundwater samples collected in wells were obtained. The correlation matrix showed strong associations between nine variables: K⁺, Ca²⁺, Na⁺, SO₄^2?, Cl^?, Mg²⁺, NO₂^?, Zn²⁺ and Sr²⁺. Principal component analysis and factor analysis showed that the cumulated variance of high and low water periods was of 83.19% and 78.55%, respectively. The variables assigned to the mineralization effect or to pollution indicators were presented by the factor analysis. The bivariate plots confirmed a mineralization model, ascribed to dissolution of geological materials, and to high levels of saline contamination attributed to leakages from sanitary systems. They also showed an increase “upstream to downstream” of the mineralization, visualization of temporal variations, and a dilution process identification of the natural mineralization during the recharge of the aquifer.

EDITOR D. Koutsoyiannis; ASSOCIATE EDITOR X. Chen     

Ion Chemistry of the Ionosphere at E- and F-Region Altitudes: A Review

The current state of knowledge of E- and F-region ion chemistry is reviewed. Considerable attention is given to the progress in the chemistry of unexcited N₂ ⁺, O₂ ⁺, NO⁺, O⁺(⁴S), N⁺, H⁺, He⁺, Fe⁺, Mg⁺, Na⁺, Ca⁺, and K⁺ ions and electronically excited O⁺(²D), O⁺(²P), O⁺(⁴P), and $ {\text{O}}^{ + } (^{2} {\text{P}}^{*} ) $ ions. Achievements in our understanding of the role of vibrationally excited N₂ ⁺, O₂ ⁺, and NO⁺ ions in the ionosphere are discussed.     

Hydrochemical Analyses and Evaluation of Groundwater Resources of North Jordan

The hydrochemical analyses of twenty-three springs were used to determine the properties and types of groundwater of the Tertiary-Quaternary Aquifer of northern Jordan. The result shows that the geological formation influences the quality of the investigated groundwater more than the anthropogenic factors. The water of the Quaternary-Tertiary aquifer is enriched in Ca⁺⁺ due to the dissolution of the nearby carbonate rocks. The investigated water has a low EC values with Ca(Na)-HCO₃ water type. Most springs belong to this hydrochemical facies except Malka. Groundwater in the Malka wells has high salinity with NaCl waters and a strong Ca(Mg)-HCO₃ facies (900 to 1000 mg/l TDS). The area long-term hydrochemical data have been also evaluated; general trend of increase of the analyzed ion was observed. Bicarbonate represents the most abundant anion in the studied water, which exceeds the permissible limits. Nitrates (NO ₃ ^? ) also exceed the permissible limit and are the most common contaminant in the investigated water. Data on dissolved major and trace elements (K⁺, Na⁺, Mg²⁺, Ca²⁺, Cl^?, SO ₄ ^2? , Fe, Zn, Cu and Pb) in the investigated water revealed that the concentrations lie within the natural background range. The positive correlation values between various ions indicate that most of ions come from same lithological sources. According to the residual sodium carbonate, and EC values, the studied springs are suitable for agricultural purposes.     

A Study: Removal of Cu(II), Cd(II), and Pb(II) Ions from Real Industrial Water and Contaminated Water Using Activated Sludge Biomass

This study aims to remove of Cu²⁺, Cd²⁺, and Pb²⁺ ions from solution and to investigate the adsorption isotherms, adsorption kinetics, and ion‐exchange affinities of these metals using waste activated sludge (AS) biomass. The adsorptions of the metals on biomass were optimal at an acidic pH value of 6.0 based on its monolayer capacities. Maximum monolayer capacities of AS biomass (q_max) were calculated as 0.478, 0.358, and 0.280 mmol g^?1 for Cu²⁺, Cd²⁺, and Pb²⁺, respectively, and the adsorption equilibrium time was found as 60 min for each metal. The adsorbed amount of metal rose with increasing of initial metal ion concentration. The equilibrium adsorption capacity of AS for initial 0.25 mmol L^?1 metal concentration was determined as 0.200, 0.167, and 0.155 mmol g^?1 for Cu²⁺, Cd²⁺, and Pb²⁺ ions, respectively. These relevant values were determined as 0.420, 0.305, and 0.282 mmol g^?1 for Cu²⁺, Cd²⁺, and Pb²⁺ ions, respectively, when initial metal concentration was 0.50 mmol L^?1. In the multi‐metal sorption system, the adsorption capacity of AS biomass was observed in the order of Cu²⁺ > Cd²⁺ > Pb²⁺. In the presence of 100 mmol L^?1 H⁺ ion, the order of ion‐exchange affinity with H⁺ was found as Cu²⁺ > Cd²⁺ > Pb²⁺. The adsorption kinetics were also found to be well described by the pseudo‐second‐order and intraparticle diffusion models. Two different rate constants were obtained as k_i1 and k_i2 and k_i1 (first stage) was found to be higher than k_i2 (second stage).     

Effects of catastrophic flooding on stream biogeochemistry in a headwater stream in Shenandoah National Park,USA

This study examined the stream chemistry changes in Staunton River (a second‐order headwater stream with an average annual discharge 704 m³ ha^?1 yr^?1, Shenandoah National Park, Virginia) resulting from a catastrophic flood in June 1995. This flood, which followed after 800 mm of rain in a 4‐day period, caused large‐scale debris flows and complete scouring of riparian soils down to bedrock in the lower 2 km of the stream, and has been estimated to be a 1000‐year flood. The flood affected stream chemistry on both short‐ and long‐term time scales. The primary short‐term response was elevations in stream concentration of Ca²⁺, Mg²⁺, and K⁺ by 59%, 87%, and 49%, respectively, for 6 months immediately following the flood. The long‐term impact of decreased concentration of all base cations and SiO₂ during summer months (8% average) lasted about 2 years. At the episodic time scale, Ca²⁺, Mg²⁺, and K⁺ flushed from soil sources during pre‐flood storms while Na⁺ and SiO₂ diluted; these trends generally reversed during post‐flood storms for 2 years. Short‐term effects are attributed to the leaching of unconsolidated soil and upturned organic matter that clogged the streambed after the flood. The long‐term and superimposed episodic impacts may have resulted from the loss of riparian soils and vegetation in the flood. Copyright © 2008 John Wiley & Sons, Ltd.     

Major ion geochemistry and nutrient behaviour in the mixing zone of the Changjiang (Yangtze) River and its tributaries in the Three Gorges Reservoir

Inorganic ions and nutrients were measured at different depths of the Xiangxi and Daninghe Rivers to explore the mixing processes of representative bays in the Three Gorges Reservoir (TGR). HCO₃⁻ and Ca²⁺ are the dominant ions. Carbonate weathering is the most important mechanism controlling the ion water chemistry; however, important differences exist between the main channel and its tributaries. Major ion levels in the TGR bays depend on hydrological mixing. Results show that the major ions of Ca²⁺, Mg²⁺, Na⁺, K⁺, Sr²⁺, SO₄²⁻ and Cl⁻ show chemically conservative behaviour during transit through the bays of the TGR. This means the ions can be used as tracers in the same way that salinity is used in estuaries to explore behaviour of other non‐conservative elements and to indicate specific source waters. In contrast, nutrients are not conserved in the mixing zone. The mixing of the main channel and tributaries and biological utilization in backwater reaches were the key factor controlling nutrient distributions in Xiangxi and Daninghe Bays. Copyright © 2010 John Wiley & Sons, Ltd.     

The solubility mechanisms of volatiles in silicate melts and their relations to crystal-andesite liquid equilibria

The anionic structure of magmatic liquids has been estimated at 1 atm and at pressures corresponding to those of the upper mantle. These estimates are based predominantly on spectroscopic data on binary metal oxide-silica and ternary metal oxide-silica-alumina melts. Structural information on melt compositions in aluminate-silica joins has been used to provide detailed information on the role of Al³⁺ in natural magma at atmospheric and high pressure.Regardless of pressure, andesitic melts may be described as combinations of chain, sheet, and three-dimensional network units. Nearly all Al³⁺ in the magmatic liquid resides in the three-dimensional network units. This Al³⁺ is locally charge-balanced with Na⁺, K⁺, Ca²⁺, and Mg²⁺. In the latter two cases, Al³⁺ and Si⁴⁺ are ordered, whereas for Na⁺ and K⁺, Si⁴⁺ and Al³⁺ are randomly mixed. Solution of water in natural magma results in the formation of new nonbridging oxygens in addition to OH groups attached to Si⁴⁺ and metal cations.On the basis of determined solution mechanisms of CO₂ and H₂O in silicate melts, thermodynamic properties of HO+CO₂, fluids and hydrous silicate melts and melting phase relations in peridotite-H₂O-CO₂, systems, it is found that natural andesitic magma in equilibrium with spinel Iherzolite in the upper mantle (10–20 kbar) must contain at least 5–7 wt.% H₂O. Andesitic magma with 5–7 wt.% H₂O in solution may be described as a mixture of Al-free three-dimensional units, sheets, and chains with a small proportion (less than 10%) of monomers.     

Hydrochemical characteristics and salinization processes of groundwater in the shallow aquifer of Eastern Laizhou Bay,China

Groundwater salinization has become a crucial environmental problem worldwide and is considered the most widespread form of groundwater contamination in the coastal zone. In this study, a hydrochemical investigation was conducted in the eastern coastal shallow aquifer of Laizhou Bay to identify the hydrochemical characteristics and the salinity of groundwater using ionic ratios, deficit or excess of each ions, saturation indices and factor analysis. The results indicate that groundwater in the study area showed wide ranges and high standard deviations for most of hydrochemical parameters and can be classified into two hydrochemical facies, Ca²⁺‐Mg²⁺‐Cl^‐ facies and Na⁺‐Cl^‐ facies. The ionic ratio, deficit or excess of each ions and SI were applied to evaluate hydrochemical processes. The results obtained indicate that the salinization processes in the coastal zones were inverse cation exchange, dissolution of calcite and dolomite, and intensive agricultural practices. Factor analysis shows that three factors were determined (Factor 1: TDS, EC, Cl^‐, Mg²⁺, Na⁺, K⁺, Ca²⁺ and SO₄^2‐; Factor 2: HCO₃^‐ and pH; Factor 3: NO₃^‐ and pH), representing the signature of seawater intrusion in the coastal zone, weathering of water–soil/rock interaction, and nitrate contamination, respectively. Copyright © 2011 John Wiley & Sons, Ltd.     

Chemical Composition of Dew Resulting from Radiative Cooling at a Semi-arid Site in Agra, India

Dew samples were collected between October 2007 and February 2008 from a suburban site in Agra. pH, conductivity, major inorganic ions (F^?, Cl^?, NO ₃ ^? , SO ₄ ^2? , Na⁺, K⁺, Ca²⁺, Mg²⁺, and NH ₄ ⁺ ), and some trace metals (Cr, Sn, Zn, Pb, Cd, Ni, Mn, Fe, Si, Al, V, and Cu) were determined to study the chemistry of dew water. The mean pH was 7.3, and the samples exhibited high ionic concentrations. Dew chemistry suggested both natural and anthropogenic influences, with acidity being neutralized by atmospheric ammonia and soil constituents. Ion deposition flux varied from 0.25 to 3.0?neq?m^?2?s^?1, with maximum values for Ca²⁺ followed by NH ₄ ⁺ , Mg²⁺, SO ₄ ^2? , Cl^?, NO ₃ ^? , Na⁺, K⁺, and F^?. Concentrations of trace metals varied from 0.13 to 48?μg?l^?1 with maximum concentrations of Si and minimum concentration of Cd. Correlation analysis suggested their contributions from both crustal and anthropogenic sources.     

Monitoring of Impact of Ferti‐irrigation by Post‐methanated Distillery Effluent on Groundwater Quality

The impact assessment of molasses‐based distillery‐effluent irrigation on groundwater quality around village Gajraula in the district of Jyotiba Phule Nagar, Uttar Pradesh, India was studied by sampling groundwater on monthly intervals consecutively for summer, winter and monsoon seasons during 2006–2007 and water quality parameters, viz. pH, electrical conductivity (EC), chloride (Cl^?), sulphate (SO), nitrate (NO), chemical oxygen demand (COD), total solids (TS), total dissolved solids (TDS), sodium (Na⁺), potassium (K⁺), calcium (Ca²⁺), magnesium (Mg²⁺), zinc (Zn²⁺), iron (Fe³⁺), and total coliforms (TC) were monitored. Results depicted that the values of all parameters decreased with increasing depth of water table. Sulphate, nitrate and potassium contents were maximal in agricultural site during monsoon while EC, Cl^?, TS, TDS, Na⁺, Ca²⁺, Mg²⁺, Zn, and Fe were maximal in industrial sites during summer. Groundwater samples of residential site harboured maximum coliforms especially during monsoon, highlighting threat to groundwater. Significant positive correlation matrix between coliforms with nitrate, sulphate and potassium ions explained their survival on these nutrients. To overcome this, important measures emphasizing improvement in effluent treatment technology matching site‐specific characteristics are recommended for eco‐friendly ferti‐irrigation.