The quality of groundwater was investigated for possible agriculture pollution in the traditional agriculture region of Strumica, situated in the southeast part of the Republic of Macedonia. Almost 200 samples of water from boreholes in 14 different points were collected and analyzed by relevant standard methods for a total content of Na+, K+, Ca2+, Mg2+, NH +, Cl-, HCO -, SO 2-, NO -, NO -, and PO 3-. The results showed that groundwater in the studied area 4 3 4 3 2 4 is generally neutral to slightly alkaline. The abundance of the major ions is Mg2+>Ca2+>K+>Na+ and HCO ->Cl->PO 3->SO 2-. Concentration range of the main 3 4 4 cations Na+, K+, Ca2+ Mg2+ and NH + is 1.40 – 36.71mg/L, 0.68 – 354.44 mg/L, 7.43 – 411.18 mg/L, 1.07 – 96.14 mg/L and < LOQ (limit of quantification) – 55.89 4 mg/L, respectively. Regarding anions Cl-, HCO -, SO 2-, NO -, NO -, and PO 3- concentration range is 4.19 – 614.31mg/L, 0.04 – 750.97 mg/L, < LOQ – 300.45 3 4 3 2 4 mg/L 0.14 – 284.44 mg/L, < LOQ – 35.85 mg/L and < LOQ – 7.80 mg/L, respectively. A multivariate statistical analysis is performed to evaluate the possible interrelationship within a set of variables. Statistical and hydrochemical analysis suggest that the quality of groundwater is mainly affected by the geological composition of the area. Factor analysis (FA) revealed five significant factors of 14 variables and account for 71.54 % of the total variance. Although nitrates are considered a significant source of widespread groundwater contamination, when it comes to agricultural areas the result didn't show any severe contamination except in the periphery of the valley which is considered to be related to the thickness of the basal lithozone represented by sandstones and the shallow aquifers.

Journal of Hydrology, 2018

The Uluova basin aquifer system (UBAS), comprised of fractured/karstic rock and multilayer basin-fill aquifers, provides water for both domestic and agricultural needs in the Elazığ province (Eastern Turkey). Although, the UBAS has been subject of large-scale hydrological modifications and controversial water management practices since late 1950s, thus far no studies have examined basinwide implications of such human perturbations in an integrated manner. In this study, GIS, geostatistics, R-mode factor analysis (R-mFA) and geochemical modeling techniques were employed to unravel the factors controlling the distribution and sources of arsenic (As) and selected potentially toxic elements (PTEs) in the stream sediment-soil and groundwater-surface water systems of the UBAS. As revealed by the results from R-mFA, three geogenic factors (F1: Clay minerals and Fe-Mn oxyhydroxides, F2: Weathering of parent materials, and F3: Sulfide oxidation in mineralized zones) govern the geochemical dynamics of the PTEs in the stream sediment/soil media. In stream sediment and soil samples, especially Ni, Cr, and Co presented significant enrichment relative to upper continental crust average composition, whereas As contents were relatively low, varying from 0.3 to 13 mg kg −1. Factors extracted from the combined water dataset (F1: Groundwater salinization and arsenic mobilization, F2: Clay minerals and Fe-Mn oxyhydroxides, F3: pH and redox conditions, and F4: Aquifer oxygenation and nitrate contamination) accounted for 72.59% of the total variance. Water-rock interaction (e.g. sulfide oxidation, carbonate dissolution, silicate hydrolysis, adsorption-desorption, ion exchange, and evaporite dissolution), dilution/mixing with fresh/saline water components, evapoconcentration, and human induced perturbations causing internal salinization and oxygenation of the UBAS were the key mechanisms controlling the chemistry of waters and mobilization of As. In the UBAS, majority of As-rich water samples are confined to central-northern half of the basin and typically display high levels of dissolved O 2 , inorganic oxyanions (HCO 3 − , SO 4 2− and of Si, B, Mo, Sb and V) and alkaline pH. Oxidation of sulfides (e.g. pyrite and arsenopyrite) found within the highly fractured Elazığ magmatics in the upland areas at north and subsequent competitive adsorption-desorption processes occurring under alkaline, oxidizing and high ionic strength aquifer conditions along the downgradient groundwater flow path play a pivotal role in the As-enrichment in the UBAS. As concentrations ranged between 0.02 and 367.2 μg L −1 in groundwater, 0.13-4842 μg L −1 in spring water, and 0.04-31.1 μg L −1 in the stream water samples, of which 20.83% exceeded the WHO provisional guideline value. In the water samples, As occurs mainly as As(V) species (HAsO 4 2− and H 2 AsO 4 −), indicated by the Eh-pH diagram and speciation calculations. The results of this study have shown that As enrichment in the UBAS can be attributed to both geogenic processes and anthropogenic activities that have modified the basin hydrology/hydrochemistry.

Environmental Earth Sciences, 2013

Groundwater of an aquifer located in the vicinity of a large coal washery near Zarand City, Iran consists of two hydrochemically differing facies, which have been informally designated as groundwater (A) and groundwater (B). Groundwater (A) is native, brackish in composition and is characterized by Na ? [ Mg 2? [ Ca 2? [ K ? and SO 4 2-[ HCO 3-[ Cl-[ NO 3-. Spearman's rank correlation coefficient matrices, factor analysis data, and values of chloroalkaline indices, C ratio and Na ? /Clmolar ratio indicate that in the groundwater (A), the ionic load of Ca 2? , Mg 2? , Na ? , K ? , SO 4 2and HCO 3 is derived essentially from weathering of both carbonates and aluminosilicates and direct cation and reverse cation-anion exchange reactions. Groundwater (B) is the polluted variant of the groundwater (A), brackish to saline in composition, and unlike the groundwater (A), consists of HCO 3 as the dominant anion. In comparison with the groundwater (A), the groundwater (B) contains higher concentrations of all ions, and its average ionic load (av. = 59.74 me/L) is 1.43 times higher than that of the groundwater (A) (av. = 41.54 me/L). Additional concentrations of Ca 2? , Mg 2? , K ? , SO 4 2-, Cland HCO 3 in the groundwater (B) are provided mainly by downward infiltrating water from the coal washery tailings pond and reverse cation-anion exchange reaction between tailings pond water and exchanger of the aquifer matrix during non-conservative mixing process of groundwater (A) and tailings pond water. Certain additional concentrations of Na ? , K ? and NO 3 in the groundwater (B) are provided by other anthropogenic sources. Quality wise, both groundwaters are marginally suitable for cultivation of salt-tolerant crops only.

Environmental Monitoring and Assessment, 2011

Romania is one of the countries that have natural arsenic groundwater problems. This paper presents the results of a study of arsenic concentration monitoring in natural mineral waters collected from 23 sampling sites located in the northern, central, and western regions of Romania. The sampling sites are both natural springs and drilled wells. The graphite furnace atomic absorption spectrometry was used for arsenic content determination. The Piper's classification principle was applied in order to find out the hydrochemical type of the analyzed waters. Depending on the concentration of arsenic, the water analyzed can be classified into three main categories: (1) mineral natural waters containing less than 10 μg/L arsenic, (2) mineral natural waters containing arsenic at concentrations several times higher than the limit of 10 μg/L but less than 100 μg/L, and (3) mineral natural waters contain-A. Tudorache · I. A. Badea (B) · L. Vlȃdescu ing arsenic at concentrations of ten to a hundred times higher than the allowed limit of 10 μg/L. The last-mentioned waters are of bicarbonatate sodium type and were sampled from seven sources only, being prohibited for human and animal use.

Bulletin of the Geological Society of Greece, 2013

A geochemical study of NW Euboea island ground waters was undertaken, in order to examine the possible effect of the chemical composition of the country rocks of the area as well as of the anthropogenic activities, to the concentration of environmentally important elements and chemical compounds in the groundwaters. NW Euboea consists of a great variety of rock types showing a wide range in mineralogical and chemical composition. The main groups of rocks occurring in NW Euboea are: i) various types of sedimentary rocks e.g. shale and chert formations, carbonate and clastic rocks, ii) ophiolitic rocks including peridotite, gabbro, serpentinite etc, and iii) epizonally metamorphosed basic igneous rocks, with schist and phyllite intercalations. A number of hot springs also occur in the area. The main anthropogenic activity in the area is the agricultural land use, as any significant industrial activity is absent. For that purpose, 45 water samples were collected and analyzed by Spectrophotometry for the main anions and by FP and AAS for major and a number of trace elements. On the basis of those analyses, a number of the water samples were selected and analyzed by ICP-AES and ICP-MS for a large group of mainly metallic trace elements. The interpretation of the analytical data showed clearly that the content of the groundwater for a significant group of trace elements (e.g. Cr, Ni, Zn) was considerably influenced by the chemical composition of the surrounding rocks, especially the ophiolitic and metamorphic rocks. The anthropogenic activities also affect the groundwater quality, near areas where the use of fertilizers and pesticides for agricultural purposes is extensive, resulting to the increase of various anion concentrations (NO3-, SO4-2, PO4-3).

Journal of Food and Nutrition Sciences, 2014

The present study investigates the total arsenic (As) content in the samples of drinking water in the Republic of Macedonia, which is obtained from different water sources, such as: springs, surface accumulations, underground accumulations and drilled wells. From January 2013 to December 2013, a total of 780 samples obtained from the public water supply systems at 35 measurement points distributed throughout the whole territory of the Republic of Macedonia were analyzed on the total As content. A flow injection atomic absorption spectrometry (FIAS) was employed for the determination of the total As content after wet digestion of the samples with nitric acid (67%, W/V) and hydrogen peroxide (30%, V/V). The results of the study revealed that in 96.7% of the tested samples, As content was below established maximum allowable concentration (MAC) of 10 µg/L. As concentrations up to 26.4 µg/L were found in the samples of drinking water that comes from the water sources located in the vicinity of Kozhuf Mountain, which is due to the mineral composition of the mountain body rich with As containing minerals: lorandite, orpiment, realgar, arsenopyrite etc. Higher As concentrations (5.47 µg/L -26.6 µg/L) were also found in the samples of drinking water obtained from the water supply system of the towns from the Dojran Municipality which are located in the vicinity of thermal-mineral area of Mala Boshka -Toplec. It can be concluded that the presence of total As in the potable water in the Republic of Macedonia comes only from natural sources.

2014

In the present study, a hydrochemical investigation was conducted in a rural area from Cluj County, Romania, in order to determine the chemical composition of groundwater and to evaluate if the investigated water sources can be used for drinking or agriculture purposes. Several groundwater samples were collected from fifteen wells in order to analyze the major dissolved ions (Na+, K+, Mg2+, Ca2+, F-, Cl-, Br-, NO2, NO3, PO4 and SO4). The analyzed waters proved to have a low level of sodium (0.27 41.87 mg/l), magnesium (0.11 – 25.17 mg/l), calcium (0.59 – 117.30 mg/l), chloride (3.33 – 97.68 mg/l) and sulphate (4.42 – 132.80 mg/l), and a high level of potassium (0.22 – 22.59 mg/l), nitrites (detected only in one sample 1.36 mg/l), nitrate (6.58 – 92.96 mg/l), fluoride (0.24 – 1.40 mg/l) and phosphate (12.44 –18.26 mg/l). The possibility of using these waters for agricultural purposes has been assessed by calculating the sodium adsorption ratio (SAR). The results of the present study ...

Applied Geochemistry, 2011

Groundwater is the main source of drinking water for the population of nearly 200,000 people in eastern Croatia. The largest town in the region is Osijek whose citizens are supplied with drinking water obtained from groundwater from the ''Vinogradi'' well field. This study investigated and determined As occurrence in groundwater of the Osijek area. Groundwater samples were taken from 18 water wells and 12 piezometers with a depth ranging between 21 and 200 m. Over the 10-a period to 2007, a mean As concentration of 240 lg L À1 was found. There was no statistically significant secular change in concentration over that period, however small but significant seasonal variations were noted, with the highest seasonal As concentrations over the period May 2006-February 2007 being observed in summer. The predominant As species observed was As(III), constituting 85% and 93% of total As in piezometers and water wells, respectively. Higher concentrations of As tended to be found in deeper wells with the mean As concentration in shallow groundwater (<50 m) and deep groundwater (>50 m) being 27 lg L À1 , and 205 lg L À1 , respectively. Geochemically, the groundwaters show similarities to those in other parts of the Pannonian Basin. Arsenic(tot) is weakly correlated with pH and Fe, negatively correlated with Mn and has no significant correlation with any of EC, COD-Mn or alkalinity.

УДК 82-3 ББК 84-4 Ф64 Шрифты предоставлены компанией «ПараТайп» Фитцпатрик Роб Спроси маму : Как общаться с клиентами и подтвердить правоту своей бизнес-идеи, если все кругом врут?. -[б. м.] : Издательские решения, 2015. -156 с. -ISBN 978-5-4474-2398-8