The Influence of a Coal-Fired Power Plant in Turkey on the Chemical Composition of Rain Water in a Certain Region

In this study, the chemical composition of the rainwater in Yatağan, which is a region surrounding a coal power plant was investigated from February to April 2002. Rainwater samples were obtained from Yatağan, located northwest of Muğla City in Turkey. pH values and concentrations of major ions (Ca²⁺, Na⁺, K⁺, , , ) in the rainwater samples were analyzed. The pH varied from 5.1 to 7.9 with an average of 6.7 which was in alkaline range considering 5.6 as the neutral pH of cloud water in equilibrium with atmospheric CO₂. In the total of 30 rain events, only three events were observed with water in the acidic range (<5.6), which occurred after continuous rains. The equivalent concentration of components followed the order: Ca²⁺ > > Na⁺ > > > K⁺ > H⁺. The anion and cation concentrations in the rainwater samples showed a high sulphate concentration (131 μEq/l), as well as high sodium (40 μEq/l) and calcium (298 μEq/l) concentrations. These values indicate that one probable source of the high sodium concentration is fly ash, after the coal burning process and the power plant can be effective on level concentrations in rainwater. In addition, the dust-rich local and surrounding limestone environment might have caused the high concentration of Ca²⁺ in rainwater of the Yatağan Basin. Due to a large contribution of these cations to the sulphate neutralization action, the rainwater of this region displays only a moderate acidity, which does not cause significant environmental impact.     

Leaching of nitrogen from calcareous soils in western Iran: a soil leaching column study

Nitrogen (N) leaching has become a matter of worldwide concern. The objectives of this study were: (1) to use soil columns to investigate the leaching of nitrate ( $ {\text{NO}}_3^{ - } $ ), ammonium ( $ {\text{NH}}_4^{ + } $ ), and nitrite ( $ {\text{NO}}_2^{ - } $ ) from calcareous soils that had received an average of 200?kg^?1 N?ha^?1?year^?1 for the previous 30?years and (2) to determine the relationship between soil properties and $ {\text{NO}}_3^{ - } $ , $ {\text{NH}}_4^{ + } $ , and $ {\text{NO}}_2^{ - } $ leaching. The soils used in this study ranged in texture from clay to sandy loam. Leaching experiments were conducted under saturation conditions and consisted of the collection of 1,047–2,524?mL of leachate (12 pore volumes (PVs)), which was equivalent to 534–1,286?mm from rainfall or irrigation. Losses of $ {\text{NO}}_3^{ - } $ ranged from 62 to 437?kg?ha^?1, while losses of $ {\text{NH}}_4^{ + } $ and $ {\text{NO}}_2^{ - } $ ranged from 2.5 to 19.3?kg?ha^?1 and 0.1 to 10.6?kg?ha^?1, respectively. Leaching rates differed between soil samples. The initial and secondary rate of $ {\text{NO}}_3^{ - } $ leaching was determined using an exponential model, and it ranged from 2.8 to 14.7?mg?kg^?1 PV^?1 and 0.11 to 0.32?mg?kg^?1 PV^?1. Greater leaching rates in the initial period could be due to leaching of $ {\text{NO}}_3^{ - } $ in solution, while the secondary leaching might be attributable to the diffusion-controlled transfer of $ {\text{NO}}_3^{ - } $ between mobile and immobile liquid phases. Analysis of variance indicated that the effects of soil type on total $ {\text{NO}}_3^{ - } $ leaching were highly significant (p?<?0.001). The results showed that soil $ {\text{NO}}_3^{ - } $ concentration was positively correlated with the peak concentration of $ {\text{NO}}_3^{ - } $ (r?=?0.86; p?<?0.01) and the total $ {\text{NO}}_3^{ - } $ leached (r?=?0.93; p?<?0.01). In addition, the total $ {\text{NH}}_4^{ + } $ leached was positively correlated with silt (r?=?0.67; p?<?0.05), clay (r?=?0.61; p?<?0.05), and pH (r?=?0.77; p?<?0.01), which suggests that soil parameters might be useful indicators of $ {\text{NO}}_3^{ - } $ and $ {\text{NH}}_4^{ + } $ leaching from calcareous soils. Nitrate leaching from soils could threaten groundwater supplies, so possible strategies for minimizing $ {\text{NO}}_3^{ - } $ leaching losses may need to be considered.     

Hydrogeochemical characterization of fluoride rich groundwater of Wailpalli watershed, Nalgonda District, Andhra Pradesh, India

The groundwater of Nalgonda district is well known for its very high fluoride content for the past five decades. Many researchers have contributed their scientific knowledge to unravel causes for fluoride enrichment of groundwater. In the present paper, an attempt has been made to relate the high fluoride content in the groundwater to hydrogeochemical characterization of the water in a fracture hard rock terrain—the Wailpally watershed. Groundwater samples collected from all the major geomorphic units in pre- and post-monsoon seasons were analyzed for its major ion constituents such as Ca^2?+?, Mg^2?+?, Na^?+?, K^?+?, CO $_{3}^{-}$ , HCO $_{3}^{-}$ , Cl^???, SO $_{4}^{-2}$ , NO $_{3}^{-}$ , and F^???. The groundwaters in the watershed have the average fluoride content of 2.79 mg/l in pre-monsoon and 2.83 mg/l in post-monsoon. Fluoride concentration in groundwater does not show perceptible change neither with time nor in space. The ionic dominance pattern is in the order of Na^?+? > Ca^2?+??> Mg^2?+??> K^??? among cations and HCO $_{3}^{-}\:\,>$ Cl^????> SO $_{4}^{-2} >$ NO $_{3}^{-} >$ F^??? among anions in pre-monsoon. In post-monsoon, Mg replaces Ca^2?+? and NO $_{3}^{-}$ takes the place of SO $_{4}^{-2}$ . The Modified Piper diagram reflect that the water belong to Ca^?+?2–Mg^?+?2–HCO $_{3}^{-}$ to Na^?+?–HCO $_{3}^{-}$ facies. Negative chloralkali indices in both the seasons prove that ion exchange between Na^?+? and K^?+? in aquatic solution took place with Ca^?+?2 and Mg^?+?2 of host rock. The interpretation of plots for different major ions and molar ratios suggest that weathering of silicate rocks and water–rock interaction is responsible for major ion chemistry of groundwater in Wailpally watershed. Chemical characteristics and evolution of this fluoride-contaminated groundwater is akin to normal waters of other hard rock terrain; hence, it can be concluded that aquifer material play an important role in the contribution of fluoride in to the accompanying water. High fluoride content in groundwater can be attributed to the continuous water–rock interaction during the process of percolation with fluorite-bearing country rocks under arid, low precipitation, and high evapotranspiration conditions.     

The hydrochemistry of groundwater in the Densu River Basin, Ghana

Hydrochemical analyses of groundwater samples were used to establish the hydrochemistry of groundwater in the Densu River Basin. The groundwater was weakly acidic, moderately mineralized, fresh to brackish with conductivity ranging from of 96.6 μS cm^???1 in the North to 10,070 μS cm^???1 in the South. Densu River basin have special economic significance, representing the countries greatest hydrostructure with freshwater. Chemical constituents are generally low in the North and high in the South. The order of relative abundance of major cations in the groundwater is Na^?+??> Ca^2?+??> Mg^2?+??> K^?+? while that of anions is Cl^????> HCO $_{3}^{-} >$ SO $_{4}^{2-} >$ NO $_{3}^{-}$ . Four main chemical water types were delineated in the Basin. These include Ca–Mg–HCO₃, Mg–Ca–Cl, Na–Cl, and mixed waters in which neither a particular cation nor anion dominates. Silicate weathering and ion exchange are probably the main processes through which major ions enter the groundwater system. Anthropogenic activities were found to have greatly impacted negatively on the quality of the groundwater.     

Specific absorption and backscattering coefficients of the main water constituents in Poyang Lake, China

Obtaining and analyzing the specific inherent optical properties (SIOPs) of water bodies is necessary for bio-optical model development and remote sensing-based water quality retrievals and, further, for related ecological studies of aquatic ecosystems. This study aimed to measure and analyze the specific absorption and backscattering coefficients of the main water constituents in Poyang Lake, China. The specific absorption and/or backscattering coefficients of the main water constituents at 85 sampling sites (47 in 2010 and 38 in 2011) were measured and analyzed as follows: (1) the concentrations of chlorophyll a (C _CHL), suspended particulate matter (C _SPM) (including suspended particulate inorganic matter (C _SPIM) and suspended particulate organic matter (C _SPOM)), and the absorption coefficients of total particulate (a _p), phytoplankton (a _ph), and non-pigment particulate (a _d) were measured in the laboratory; (2) the total backscattering coefficients at six wavelengths of 420, 442, 470, 510, 590, and 700 nm, including the contribution of pure water, were measured in the field with a HydroScat-6 backscattering sensor, and the backscattering coefficients without the contribution of pure water (b _b) were then derived by subtracting the backscattering coefficients of pure water from the total backscattering coefficients; (3) the specific absorption coefficients of total particulate ( $ a_{\mathrm{p}}^{ * } $ ), phytoplankton ( $ {a_{{\mathrm{ph}}}}^{ * } $ ), and non-pigment particulate ( $ a_{\mathrm{d}}^{ * } $ ) were calculated by dividing a _p, a _ph, and a _d by C _SPM, C _CHL, and C _SPIM, respectively, while the specific backscattering coefficients of total suspended particulate matter ( $ b_{\mathrm{b}}^{ * } $ ) were calculated by dividing b _b by C _SPM; and (4) the $ {a_{{\mathrm{ph}}}}^{ * } $ , $ a_{\mathrm{d}}^{ * } $ , $ a_{\mathrm{p}}^{ * } $ and $ b_{\mathrm{b}}^{ * } $ of the remaining samples (46 in 2010 and 36 in 2011) were visualized and analyzed, and their relations to C _CHL, C _SPIM or C _SPM were studied, respectively. The main results are summarized as follows: (1) the $ {a_{{\mathrm{ph}}}}^{ * } $ values at 440 nm were 0.0367–0.7203 m²?mg^?1 with a mean of 0.1623?±?0.1426 m²?mg^?1 in 2010 and 0.0319–0.7735 m²?mg^?1 with a mean of 0.3145?±?0.1961 m²?mg^?1 in 2011; there existed significant, negative, and moderate correlations between $ {a_{{\mathrm{ph}}}}^{ * } $ and C _CHL at 400–700 nm in 2010 and 2011 (p?<?0.05); (2) The $ a_{\mathrm{d}}^{ * } $ values at 440 nm were 0.0672–0.2043 m²?g^?1 with a mean of 0.1022?±?0.0326 m²?g^?1 in 2010 and 0.0559–0.1347 m²?g^?1 with a mean of 0.0953?±?0.0196 m²?g^?1 in 2011; there existed negative correlations between $ a_{\mathrm{d}}^{ * } $ and C _SPIM, while the correlations showed overall decreasing and increasing trends before and after around 575 nm with increasing wavelengths, respectively; (3) The $ a_{\mathrm{p}}^{ * } $ values at 440 nm were 0.0690–0.1929 m²?g^?1 with a mean of 0.1036?±?0.0298 m²?g^?1 in 2010 and 0.0571–0.1321 m²?g^?1 with a mean of 0.1014?±?0.0191 m²?g^?1 in 2011, and the negative correlations between $ a_{\mathrm{p}}^{ * } $ and C _SPM were found in both years; (4) The $ b_{\mathrm{b}}^{ * } $ at the six wavelengths generally decreased with increasing wavelengths, while the $ b_{\mathrm{b}}^{ * } $ values at 420 nm were lower than those at 442 nm for some samples; the correlation between $ b_{\mathrm{b}}^{ * } $ and C _SPM increased with increasing wavelength. Such results can only represent the SIOPs during the sampling time periods, and more measurements and analyses considering different seasons need to be carried out in the future to comprehensively understand the SIOPs of Poyang Lake.     

Factors controlling the salinity in groundwater in parts of Guntur district, Andhra Pradesh, India

Groundwater chemistry has been studied to examine the associated hydrogeochemical processes operating for the development of salinity in the groundwater in parts of Guntur district, Andhra Pradesh, India. The study area is underlain by charnockites and granitic gneisses associated with schists of the Precambrian Eastern Ghats. Groundwater is the main resource for irrigation besides drinking. Chemical parameters, pH, EC, TDS, Ca²⁺, Mg²⁺, Na⁺, K⁺, , , Cl⁻, , , F⁻ and SiO₂, are taken into account. Groundwater is of brackish type. Na⁺−Cl⁻ facies dominates the groundwater. Examination of compositional relations and mineral saturation states shows that the ion exchange of Ca²⁺ for adsorbed Na⁺, evapotranspiration, dissolution of soil salts, dissolution of NaCl and CaSO₄, and precipitation of CaCO₃ are the dominant hydrogeochemical processes associated with the groundwater composition in the area. Evapotranspiration causes accumulation of salts in the soil/weathered zone. These salts reach the water table by leaching through infiltrating recharge water. A positive relation between depth to water table and TDS with season supports this inference. The effects of human activities, such as intensive and long-term irrigation, irrigation-return-flow, application of unlimited agricultural fertilizers and recycling of saline groundwater, act to further increase the salinity in the groundwater. Therefore, the groundwater quality increases towards the flow path, while the post-monsoon groundwater shows higher concentrations of TDS, Na⁺, Mg²⁺, Cl⁻, , , F⁻ and SiO₂ ions. The study could help to understand the hydrogeochemical characteristics of the aquifer system for taking effective management measures to mitigate the inferior groundwater quality for sustainable development.     

Major ion chemistry and hydrochemical studies of groundwater of Bangalore South Taluk, India

Groundwater is almost globally important for human consumption as well as for the support of habitat and for maintaining the quality of base flow to rivers, while its quality assessment is essential to ensure sustainable safe use of the resources for drinking, agricultural, and industrial purposes. In the current study, 28 groundwater samples were collected around Vrishabhavathi valley region of Bangalore South Taluk to assess water quality and investigate hydrochemical nature by analyzing the major cations (Ca^2?+?, Mg^2?+?, Na^?+?, K^?+?) and anions $(\text{HCO}_{3}^{-}$ , Cl^???, F^???, $\text{SO}_{4}^{2-}$ , $\text{NO}_{3}^{-}$ , $\text{PO}_{4}^{3-}$ , $\text{CO}_{3}^{2-})$ besides some physical and chemical parameters (pH, electrical conductivity, alkalinity, and total hardness). Also, geographic information system-based groundwater quality mapping in the form of visually communicating contour maps was developed to delineate spatial variation in physico-chemical characteristics of groundwater samples. Piper trilinear diagram was constructed to identify groundwater groups (hydrochemical facies) using major anionic and cationic concentration and it was found that majority of the samples belongs to $\text{Ca}^{2+}-\text{Mg}^{2+}-\text{Cl}^{-}-\text{SO}_{4}^{2-}$ and $\text{Ca}^{2+}-\text{Mg}^{2+}-\text{HCO}_{3}^{-}$ hydrochemical facies. Wilcox classification and US Salinity Laboratory hazard diagram suggests that 92.86% of the samples were falling under good to permissible category and C3–S1 groups, respectively, indicating high salinity/low sodium.     

Evaluation of groundwater suitability for domestic,irrigational, and industrial purposes: a case study from Thirumanimuttar river basin,Tamilnadu, India

The Thirumanimuttar sub-basin forms an important groundwater province in south India, facing serious deficiency in both quality and quantity of groundwater due to increased demand associated with rapid population explosion, agricultural growth and industrial activities. A total of 194 groundwater samples were collected and 15 water quality parameters were analyzed using standard procedures. Na⁺, Cl⁻, Ca^2 +, HCO₃^-_{3}^{-}, Mg^2 + and SO₄^2-_{4}^{2-} concentration ions are more dominant in both seasons. The total dissolved solids and electrical conductivity was observed good correlation with Na⁺, Cl⁻, HCO₃^-_{3}^{-}, Ca^2 +, Mg^2 +, Cl⁻, PO₄^3-_{4}^{3-} and NO₃^- _{3}^{- } ions indicating dominance of plagioclase feldspar weathering, anthropogenic input and over drafting of groundwater irrespective of seasons. The Hill–Piper diagram indicates alkaline earths exceed the alkalis, an increase of weak acids was noted during both the seasons. For assessing the groundwater for irrigation suitability parameters like total hardness, sodium adsorption ratio, residual sodium carbonate (RSC), permeability index, and sodium percentage are also calculated. Permanent hardness was noted in higher during both the seasons due to discharge of untreated effluents and ion exchange process. The RSC indicates 56% of the samples are not suitable for irrigation purposes in both seasons, if continuously used will affect the crop yield. From the results, nearly 72% of the samples are not suitable for irrigation.     

Hydrochemistry of Wet Atmospheric Precipitation Over an Urban Area in Northern Indo-Gangetic Plains

Rain water samples were collected to study the chemical composition of wet atmospheric precipitation (first event) over the Lucknow city in the northern Indo-gangetic alluvial plains. The samples were collected in the month of July, 2005 from different sites. The wet precipitation samples were analyzed for pH, EC, major ions (, Cl⁻, , , , F⁻, Na⁺, K⁺, Ca²⁺, Mg²⁺, ) and heavy metals (As, Cd, Al, Co, Cr, Cu, Fe, Mn, Mo, Ni, Hg, Pb, Se, Sn, Ti, V, Zn). The pH values of wet precipitation samples ranged between 6.5 and 8.7. The analysis of linear regression applied to the set of studied variables and computation of neutralization factors showed that neutralization occurred in precipitation samples and Ca²⁺ had the maximum neutralization capacity. It was found that Cl⁻, , Ca²⁺, Mg²⁺, Na⁺ and K⁺ in the precipitation samples originated mainly from crustal/anthropogenic sources in the region. On an average Fe, and Al accounted for >72% of the total concentration of trace metals in the wet precipitation samples followed by Zn (>10%). Enrichment factors calculated for heavy metals over reference background level in seawater and Earth’s crust showed relatively higher enrichment of Zn. The principal component analysis (PCA) identified the possible sources of ionic species and heavy metals in the wet precipitation samples.     

Study of evaluation of groundwater in Gadilam basin using hydrogeochemical and isotope data

Gadilam river basin has gained its importance due to the presence of Neyveli Lignite open cast mines and other industrial complexes. It is also due to extensive depressurization of Cuddalore aquifer, and bore wells for New Veeranam Scheme are constructed downstream of the basin. Geochemical indicators of groundwater were used to identify the chemical processes that control hydrogeochemistry. Chemical parameters of groundwater such as pH, electrical conductivity, total dissolved solids, sodium (Na^?+?), potassium (K^?+?), calcium (Ca^?+?), magnesium (Mg^?+?), bicarbonate $({\rm HCO}_{3}^{-})$ , sulfate $({\rm SO}_{4}^{-})$ , phosphate $({\rm PO}_{4}^{-})$ , and silica (H₄SiO₄) were determined. Interpretation of hydrogeochemical data suggests that leaching of ions followed by weathering and anthropogenic impact controls the chemistry of the groundwater. Isotopic study reveals that recharge from meteoric source in sedimentary terrain and rock–water interaction with significant evaporation prevails in hard rock region.     

Chemical speciation in mining affected waters: the case study of Asarel-Medet mine

The inorganic chemical species in Maresh and Luda Yana rivers affected by the Cu– Mo Asarel-Medet mine, Bulgaria were determined during a low-flow and a high-flow period. The mining activities, the weathering and the oxidation processes strongly influenced the physicochemical processes in the whole water system. The main pollution source was a small lake receiving the acid effluents of the mining activities. High levels of SO₄ ^2???, Cu, Mg, Al, Mn and Fe were determined at the mining polluted and affected stations. Cu^2?+? and CuCO₃ ⁰ species (1:1) were present in the reference waters and Cu^2?+? and CuSO₄ ⁰ species (1:1) in the polluted and affected waters; Cu^2?+? species was dominating downstream. Me^2?+? followed by $\rm{MeSO}_{4}^{\kern3pt{0}}$ (Me = Mn, Zn, Cd and Pb), $\rm{PbCO}_{3}^{\kern3pt{0}}$ and $\rm{PbHCO}_{3}^{\kern3pt{+}}$ species as well as $\rm{Fe(OH)}_{2}^{\kern3pt{+}}$ , $\rm{Al(OH)}_{4}^{\kern3pt{-}}$ , $\rm{Al(OH)}_{2}^{\kern3pt{+}}$ , $\rm{Al(OH)}_{3}^{\kern3pt{0}}$ were prevailing in the system. $\rm{MeSO}_{4}^{\kern3pt{+}}$ and $\rm{Me(SO}_{4})_{2}^{\kern3pt{-}}$ (Me = Fe, Al), $\rm{Me(SO}_{4})_{2}^{\kern3pt{2-}}$ (Me = Zn, Cd and Pb), $\rm{Me(SO}_{4})_{3}^{\kern3pt{4-}}$ (Me = Zn, Cd) and $\rm{Cd(SO}_{4})_{4}^{\kern3pt{6-}}$ species polluted and affected waters. The major elements K and Na were mainly Me^?+? species, whereas Ca and Mg were Me^2?+? and $\rm{MeSO}_{4}^{\kern3pt{0}}$ species in different ratios. The concentration of concentration of $\rm{NO}_{2}^{\kern3pt{-}}$ , $\rm{NO}_{3}^{\kern3pt{-}}$ and $\rm{NH}_{4}^{\kern3pt{+}}$ species as well as complex phosphorous species such as H₂ $\rm{PO}_{4}^{\kern3pt{-}}$ , $\rm{FeHPO}_{4}^{\kern3pt{+}}$ , $\rm{HPO}_{4}^{\kern4pt{2-}}$ , $\rm{CaPO}_{4}^{\kern3pt{-}}$ , $\rm{CaHPO}_{4}^{\kern3pt{0}}$ and $\rm{MgHPO}_{4}^{\kern3pt{0}}$ were also calculated. The trace element concentrations decreased downstream due to dilution, sorption processes and precipitation, but the percentage of free metal species, which are more toxic, increased. An exception was iron and aluminum of which the dominant hydroxy colloidal and sulphate species were easily incorporated into the suspended phase.     

Atmospheric concentrations of nitric acid, sulfur dioxide, particulate nitrate and particulate sulfate, and estimation of their dry deposition on the urban- and mountain-facing sides of Mt. Gokurakuji, Western Japan

Atmospheric concentrations of nitric acid (HNO₃), sulfur dioxide (SO₂), particulate nitrate and particulate sulfate on the urban- and mountain-facing sides of Mt. Gokurakuji were measured from November 2002 to October 2003, in order to evaluate the effects of anthropogenic activity on air quality and dry deposited nitrate and sulfate on the surfaces of pine foliage. The results showed that HNO₃, SO₂ and concentrations were significantly higher (P < 0.05) on the urban-facing side (1.54, 2.48 and 0.65 μg m⁻³, respectively) than the mountain-facing side (0.67, 1.19 and 0.37 μg m⁻³, respectively), while concentrations did not differ significantly between the two sides (urban-facing: 2.80 μg m⁻³; mountain−facing: 2.05 μg m⁻³). Indirect estimates of dry deposition rates of nitrate and sulfate to the surfaces of pine foliage based on the measured concentrations approximately agreed with the measured values determined by the foliar rinsing technique in a previous study. It was found that HNO₃ was the major source (approximately 80%) of dry deposited nitrate on pine foliage, while the contribution from was about equal to that from SO₂. In conclusion, HNO₃ and SO₂ appear to be dominant species reflecting higher dry deposition rates of nitrate and sulfate on the urban-facing side compared to the mountain-facing side of Mt. Gokurakuji.     

Major ion chemistry of shallow groundwater of a fast growing city of Central India

Nagpur City located in semiarid area of central India is a fast-growing industrial centre. In recent years, rapid development has created an increased demand for drinking water, which is increasingly being fulfilled by groundwater abstraction. The present study was undertaken to assess major ion chemistry of shallow groundwater to understand geochemical evolution of groundwater and water quality for promoting sustainable development and effective management of groundwater resources. A total of 47 water samples were collected from shallow aquifer of selected parts of the city and the water chemistry of various ions viz. Ca^2 +, Mg^2 +, Na⁺, K⁺, CO₃  ^2-_{3}^{\ \, 2-}, HCO₃  ^-_{3}^{\ \, -}, Cl⁻, SO₄  ^2-_{4}^{\ \,2-} and NO₃  ^-_{3}^{\ \,-} are carried out. The chemical relationships in Piper diagram identify Ca–HCO₃–Cl and mixed Ca–Na–HCO₃–Cl as most prevalent water types. Alkaline earth exceeds alkalis and weak acids exceed strong acids. Ionic ratios and Gibb’s diagram suggest that silicate rock weathering and anthropogenic activities are the main processes that determine the ionic composition in the study area. The nitrate appeared as a major problem of safe drinking water in this region. We recorded highest nitrate concentration, i.e., 411 mg/l in one of the dug well. A comparison of groundwater quality in relation to drinking water quality standards revealed that about half of the shallow aquifer samples are not suitable for drinking.     

Twenty-year inter-annual trends and seasonal variations in precipitation and stream water chemistry at the Bear Brook Watershed in Maine, USA

Mean annual concentration of ${\textrm{SO}}_{4}^{2-}$ in wet-only deposition has decreased between 1988 and 2006 at the paired watershed study at Bear Brook Watershed in Maine, USA (BBWM) due to substantially decreased emissions of SO₂. Emissions of NO_x have not changed substantially, but deposition has declined slightly at BBWM. Base cations, ${\textrm{NH}}_{4}^{+}$ , and Cl^??? concentrations were largely unchanged, with small irregular changes of <1 μeq L^???1 per year from 1988 to 2006. Precipitation chemistry, hydrology, vegetation, and temperature drive seasonal stream chemistry. Low flow periods were typical in June–October, with relatively greater contributions of deeper flow solutions with higher pH; higher concentrations of acid-neutralizing capacity, Si, and non-marine Na; and low concentrations of inorganic Al. High flow periods during November–May were typically dominated by solutions following shallow flow paths, which were characterized by lower pH and higher Al and DOC concentrations. Biological activity strongly controlled ${\textrm{NO}}_{3}^{-}$ and K^?+?. They were depressed during the growing season and elevated in the fall. Since 1987, East Bear Brook (EB), the reference stream, has been slowly responding to reduced but still elevated acid deposition. Calcium and Mg have declined fairly steadily and faster than ${\textrm{SO}}_{4}^{2-}$ , with consequent acidification (lower pH and higher inorganic Al). Eighteen years of experimental treatment with (NH₄)₂SO₄ enhanced acidification of West Bear Brook’s (WB) watershed. Despite the manipulation, ${\textrm{NH}}_{4}^{+}$ concentration remained below detection limits at WB, while leaching of ${\textrm{NO}}_{3}^{-}$ increased. The seasonal pattern for ${\textrm{NO}}_{3}^{-}$ concentrations in WB, however, remained similar to EB. Mean monthly concentrations of ${\textrm{SO}}_{4}^{2-}$ have increased in WB since 1989, initially only during periods of high flow, but gradually also during base flow. Increases in mean monthly concentrations of Ca^2?+?, Mg^2?+?, and K^?+? due to the manipulation occurred from 1989 until about 1995, during the depletion of base cations in shallow flow paths in WB. Progressive depletion of Ca and Mg at greater soil depth occurred, causing stream concentrations to decline to pre-manipulation values. Mean monthly Si concentrations did not change in EB or WB, suggesting that the manipulation had no effect on mineral weathering rates. DOC concentrations in both streams did not exhibit inter- or intra-annual trends.     

Exports of dissolved ammonium (NH4 +) during storm events across multiple catchments in a glaciated forested watershed

Storm event exports of dissolved were explored for multiple events in the Point Peter Brook watershed (PPBW), a glaciated, forested watershed located in Western New York, USA. Investigations were performed across four catchments (1.6–696 ha) with varying topography and the extent of surface-saturated areas. While wetland and riparian waters were important sources of during non-storm periods, throughfall and litter leachate were the dominant contributors of during storm events. Ammonium concentrations in catchment discharge displayed a sinusoidal seasonal pattern with a maximum during early spring (March) and a minimum in late summer (August–September). Storm event concentrations of in streamflow were much greater than baseflow values and showed a consistent temporal pattern with an increase in concentrations on the hydrograph rising limb, a peak at or before the discharge peak, followed by a decline in concentrations. Storm event patterns of DON were similar to while the patterns of differed from for the summer and fall events. The storm event expression of was attributed to throughfall and throughfall-mediated leaching of the litter layer. The reactive behavior of precluded its use in an end member mixing model (EMMA) for predicting streamflow concentrations. While concentrations of in precipitation and streamflow were high for the spring events, exports of in streamflow were highest for the large and intense storm events. Baseflow concentrations increased with the percent wetland/saturated area in the catchment but the same trend did not hold for storm-event concentrations.     

Leaching of nitrogen, phosphorus, TOC and COD from the biosolids of the municipal wastewater treatment plant of Thessaloniki

Biosolids from the WWTP of Thessaloniki were examined for the leaching of phosphorus (as ), nitrogen (as and ), and organic matter (as TOC and COD), using two tests: (1) a pH static leaching test and (2) a characterization test, relating contaminant release to the liquid to solid (L/S) ratio. Moreover, a Microtox toxicity test was conducted, to examine the pH dependency of the toxicity of the sludge leachate on the Vibrio fischeri bacterium. Maximum phosphorus release was observed at pH < 3 and at pH > 10. Ammonium nitrogen exhibited maximum leachability at near neutral pH conditions, while nitrate nitrogen exhibited a mild increase in the leachate, as the leachant pH increased from 2 to 12. Both TOC and COD exhibited an increase in the leachate concentration, as the leachant pH was increased from 2 to 12. Ecotoxicological analysis showed that maximum toxicity occurred at very low and very high pH-conditions. As liquid-to-solid ratio increased, the leachate concentration (in mg/l) of all parameters studied decreased. The results of the study were used to conduct a release assessment estimate for the case of Thessaloniki.     

Groundwater geochemistry in the Alisadr, Hamadan, western Iran

The chemical composition of 59 well water samples throughout the Alisadr area, Hamadan, western Iran was determined in order to describe the background ion concentration and to identify the major hydrogeochemical processes that control the observed groundwater chemistry. The hydrochemical types, Ca–HCO₃, Ca–SO₄, dominate the largest part of the groundwater followed by water types Ca–Cl and Mg–HCO₃. Total hardness indicated that 30% of groundwater samples fell in the very hard water category. Ninety-seven percent of the water samples showed nitrate ( ${\rm NO}_{3}^{-})$ concentrations above the human affected value (13 mg l^???1 ${\rm NO}_{3}^{-})$ , while 15% exceeded the maximum acceptable level (50 mg l^???1 ${\rm NO}_{3}^{-})$ according to WHO regulations. With respect to sodium adsorption ratio, the groundwater can be used for irrigation on almost all soils with little danger of the developing harmful levels of exchangeable Na^?+?. But with respect to electrical conductivity, the water quality for irrigation was low to medium, providing the necessary drainage to avoid the buildup of toxic salt concentrations. Geochemical modeling using PHREEQC enabled prediction of the saturation state of minerals and indicated the dissolution and precipitation reactions occurring in the groundwater. Groundwaters were undersaturated with respect to amorphous silica. Stability diagram indicated that the dominant cluster of groundwater samples fell into the K-feldspar field.     

Sulfate exports from multiple catchments in a glaciated forested watershed in western New York, USA

Sulfate () concentrations and fluxes were studied for multiple storm events in the Point Peter Brook watershed, a glaciated, forested watershed located in Western New York, USA. Investigations were performed across one large (696 ha) and three small (1.6–3.4 ha) catchments with varying extent of riparian and wetland areas. Concentrations of in groundwater sources (mean values: 238–910 μmol_c L⁻¹) were considerably greater than concentrations recorded for rainfall (60 μmol_c L⁻¹) and throughfall (72–129 μmol_c L⁻¹). Seasonality in concentrations was most pronounced for valley-bottom riparian waters with maximum concentrations in late winter–spring (February–March) and a minimum in late summer (August). Concentrations of in wetland water were considerably less than riparian water indicating the likelihood of reduction in anoxic wetland conditions. Storm events displayed a dilution pattern in concentrations with a minimum coinciding with the maximum in throughfall contributions. End member mixing analysis (EMMA) was able to predict the storm event concentrations of for four of the six comparisons. Concentrations of at the outlet of the large (696 ha) catchment were much greater than values recorded for the smaller catchments. Exports of in streamflow exceeded the inputs from atmospheric deposition suggesting that watersheds like Point Peter Brook may not show any immediate response to decreases in atmospheric deposition.     

Assessment of dry season surface, ground, and treated water quality in the Cape Coast municipality of Ghana

This aim of this monitoring was to assess water quality in a dry season for the Cape Coast municipality in Ghana, which has been experiencing chronic water shortages. Fifteen different sampling stations—four surface, five ground, and six tap water samples—were analyzed for physicochemical and microbiological parameters during January to April 2005. Levels or trends in water quality that may be deleterious to sensitive water uses, including drinking, irrigation, and livestock watering have been noted with reference to well-established guidelines. Exceedances to some health-based drinking water guidelines included positive coliform for various water samples; pH for all groundwater samples (pH 5.9 ± 0.3); conductivity for 50% groundwater; color for about a third of groundwater and tap water; Mn for 44% tap water, 67% groundwater, and 50% surface water samples. The World Health Organization laundry staining Fe guideline of 0.3 mg/l was exceeded by 75% of surface water, 44% tap water, and 53% groundwater samples. The corresponding Mn guideline of 0.1 mg/l was exceeded by all the water samples. Respectively, all surface water samples and also 75% of the surface water exceeded some known Cu and Zn guideline for the protection of aquatic life. Compared to some historic data for Fosu Lagoon, the current study shows a lowering of ~1 pH unit, increase of ~65% $\text{NH}_{3}$ , one to two orders of magnitude increase in PO $_{4}^{{3}^{-}}$ , and more than two orders of magnitude increase in NO $_{3}^{-}$ . In several instances, tap water samples collected at the consumers’ end of the distribution system did not reflect on the true quality of the treated water. Mn, SO $_{4}^{{2}^{-}}$ , PO $_{4}^{{3}^{-}}$ , Cu, and Zn were among the chemical contaminations observed to occur in the distribution system.     

Fertigation effect of distillery effluent on agronomical practices of Trigonella foenum-graecum L. (Fenugreek)

The fertigation effect of distillery effluents concentrations such as 5%, 10%, 25%, 50%, 75% and 100% were studied on Trigonella foenu-graecu (Pusa early bunching) along with control (bore well water). On irrigation of soil with different effluents up to 90 days of harvesting, it was observed that there was a significant effect on moisture content (P < 0.001), EC, pH, Cl⁻, total organic carbon (TOC), HCO₃^-_{3}^{-}, CO₃^-2_{3}^{-2}, Na⁺, K⁺, Ca^2 +, Mg^2 +, Fe^2 +, TKN, NO₃^2-_{3}^{2-}, PO₄^3-_{4}^{3-}, and SO₄^2-_{4}^{2-} (P < 0.0001) and insignificant effect on WHC and bulk density (P > 0.05).There was no significant change in the soil texture of the soil. Among various concentrations of effluent irrigation, the irrigation with 100% effluent concentration decreased pH (16.66%) and increased moisture content (30.82%), EC(84.13%), Cl⁻ (292.37%), TOC (4311.61%), HCO₃^-_{3}^{-} (27.76%), CO₃^-2_{3}^{-2} (32.63%), Na⁺ (273%), K⁺ (31.59%), Ca^2 + (729.76%), Mg^2 + (740.47%), TKN (1723.32%), NO₃^2-_{3}^{2-} (98.02%), PO₄^3-_{4}^{3-} (337.79%), and SO₄^2-_{4}^{2-} (77.78%), Fe^2 + (359.91%), Zn (980.48%), Cu (451.51%), Cd (3033.33%), Pb (2350.00%), and Cr (2375.00%) in the soil. The agronomical parameters such as shoot length, root length, number of leaves, flowers, pods, dry weight, chlorophyll content, LAI, crop yield, and HI of T. foenum-graecum were recorded to be in increasing order at low concentration of the effluent, i.e., from 5% to 50% and in decreasing order at higher effluent concentration, i.e., from 75% to 100% as compared to control. The enrichment factor of various heavy metals was ordered for soil Cd>Cr> Pb>Zn>Cu>Fe and for T. foenum-graecum plants Pb>Cr>Cd>Cu>Zn>Fe after irrigation with distillery effluent.