Wyniki wyszukiwania - Biblioteka Nauki

1

Uzdatnianie wody w warstwie wodonośnej - dobre i złe doświadczenia

100%

Górski J.

|

2005

|

tom nr 1

14, 16

2

Assessment of groundwater mineralization in the arid steppe region of the Messaad plateau aquifer, Southern Algeria

84%

Brahmi S. , Rahmani B. , Nesrat A. , Djamal C. , Brahmi S.

|

tom no. 1

101--116

EN

Water scarcity is severely high in the North Africa and the Middle East (MENA) regions. The deterioration of water quality has an impact on the human health as well as on the development of agricultural activities, especially in arid regions, where precipitations are less frequent. The aim of this work is to identify and evaluate the chemistry of the groundwater aquifer in the region of Messaad plateau. This region is located 370 km south of Algiers in southern Algeria. A dozen of samples were collected from wells and analyzed using physic-chemical technics, and the results were processed statistically. The distribution of the conductivity values and the various chemical parameters suggest that the groundwater in the Messad wadi area is overall highly mineralized, with the EC ranging from 550 μS . cm–1 to 8790.13 μS . cm–1, with a predominance of calcium sulphate facies and calcium chloride facies. The level of mineralization noted in the southern and southeastern portions of the research area sheds light on the source of natural contamination. The SO42–, Cl– , Ca2+ , Na+ ions are the most important factors influencing the electrical conductivity of water and the groundwater chemistry. These ions are the result of the continuous dissolution of gypsum and halite in the clays and marls of the Barremian formations.

3

Wpływ współczynnika filtracji materiału aktywnego na skuteczność technologii PRB

84%

Suponik T.

|

tom T. 5, z. 4

231-243

PL

W technologii PRB zanieczyszczenia usuwane są bezpośrednio w warstwie wodonośnej przez przepływ skażonego strumienia wód podziemnych przez wypełnioną odpowiednim materiałem (aktywnym) barierę aktywną. W artykule, na podstawie modelowania hydrogeologicznego prowadzonego za pomocą programu VISUAL MODFLOW, przedstawiono i udowodniono następującą zasadę: aby zwiększyć skuteczność działania typu Funnel-and-Gate Open technologii PRB przez zwiększenie szerokości strefy oczyszczania, stosunek współczynnika filtracji materiału aktywnego do współczynnika filtracji warstwy wodonośnej (kma/kww) powinien przyjąć wartość 6. W pracy wzięto jednak pod uwagę możliwość napływu drobnych cząstek do bariery aktywnej, wytrącania się osadów w materiale aktywnym oraz nadmiernego przyrostu biomasy, które to czynniki mogą zmniejszyć zdolność filtracyjną materiału aktywnego. W konsekwencji założono więc, w zgodzie z pracami [1, 2], iż stosunek kma/kww powinien wynosić 10. Rozwiązanie to daje pewność, że zmniejszenie się wartości współczynnika filtracji materiału aktywnego na skutek przemian geochemicznych i biochemicznych oraz napływu cząstek, nie wpłynie na szerokość strefy oczyszczania. Przedstawione rozwiązanie może więc zapewnić skuteczne i długotrwałe oczyszczanie wód podziemnych w typie Funnel-and-Gate technologii PRB.

EN

PRB technology is a technique of groundwater remediation where contaminants are removed from an aąuifer by the flow through a permeable reactive barrier (PRB) filled with a special material called a "reactive material". In this paper, on the basis of hydrogeologie modelling run with the use of VISUAL MODFLOW program, the following rule was presented and proved: in order to inerease PRB efficacy (in Funnel-and-Gate Open System) by inereasing the hydraulic capture zone width, the ratio of the reactive materiał hydraulic conductivity to the aąuifer hydraulic conductivity (kma/kww) should take the value of six. Due to inflows of particles into reactive materiał, precipitate formation and biomass creation in it, the author took into consideration the possibilities of reduction the hydraulic conductivity of reactive materiał. Therefore, it was assumed, according to papers [1, 2], that the ratio of kma/kww should amount to 10. This value gives certainty that reduction in reactive materiał hydraulic conductivity due to geochemical and biochemical processes, and inflows of particles into reactive materiał, will not impact on the hydraulic capture zone width. The above mentioned solution can ensure effective and long-lasting treatment process in reactive barrier of Funnel-and-Gate Open System.

4

Skuteczność usuwania żelaza z wody w warstwach wodonośnych

84%

Hurynovich A. , Wawrzeniuk P.

|

2011

|

tom Nr 26

230-236

PL

Artykuł przedstawia wyniki badań naukowych w celu stworzenia planu modernizacji systemu usuwania żelaza z wód podziemnych na istniejącym ujęciu wód podziemnych w "Jurowcach".

EN

The article presents the results of scientific research in order to create a plan to upgrade the system to remove iron from groundwater at the mouth of the existing groundwater intake in Jurowce.

5

Groundwater investigation in saharan areas using statistical and stable isotope approaches – El Golea central south of Algeria case study

84%

Boucenna F. , Fenazi B. , Boukoffa M.

|

tom no. 1

7--21

EN

Groundwater quality determination and age estimation in a desert landscape of El Golea province situated in the south of Algeria has been investigated in the present research paper. For this regard, 57 water samples were collected from an aquifer composed of two superimposed systems; phreatic and deep continental intercalary (CI) aquifers which are a part of the Northern Sahara Aquifer System (NWSAS). Samples were analyzed to assess the age and water quality using descriptive, multivariate statistics (PCA and HCA) and stable isotopes. It is revealed that more than 71% of the IC points are characterized by a water type (Ca2+, Mg2+) (HCO3 – )2 and more than 83% of the TC samples are defined by a water type (Ca2+, Na+) (HCO3 – , SO4 2 – ) and very high salt ions contents due to the influence of surface water, evaporate leaching and irrigation water return. The isotopic composition of samples of phreatic and CI aquifers shows a clear difference between the two qualities of water. The phreatic aquifer is characterized by the δ18O range from –4.68 to –6.1, whereas δ2H from –47.25 to –59.48 and CI with values of the δ18O range from –5.96 to –7.6, and δ2H range between –53.7 and –65.78 isotopic signature. The unconfined aquifer above IC forms a special case of a mixture of ancient water from deep horizons and recent water strongly enriched from shallow horizon lands.

6

Geophysical approach for assessment of seawater intrusion in the coastal aquifer of Wadi Nador (Tipaza, Algeria)

84%

Bouderbala A. , Remini B.

|

tom Vol. 62, no. 6

1352--1372

EN

The aquifer of Nador has suffered significant salinization due to seawater intrusion. It was strongly exploited during the 1980s and 1990s. A piezometric analysis in April 2012 showed the piezometric level to lie at 0 m a.s.l. over the plain; as a result, this aquifer is highly sensitive to the marine intrusion with an electrical conductivity of the groundwater in of exceeds 2500 μS/cm and so there are no abstractions for irrigation or drinking purpose from these sectors. The geoelectric study also showed the lateral variation in the electrical resistivity for two moments separated in time by more than 45 years. The fall in resistivity may be due to the encroachment of seawater into previously freshwater zones and/or infiltration during the era of pumped abstractions downstream. The resistivity surveys reveal two distinct sectors: the saturated aquifer in brackish and saltwater having resistivity values to 36-10 Ωm, which extends nearly 1600 m inland.

7

Application of Multivariate Statistical Techniques for Characterization of Groundwater Quality in the Coastal Aquifer of Nador, Tipaza (Algeria)

84%

Bouderbala A. , Remini B. , Saaed Hamoudi A. , Pulido-Bosch A.

|

tom Vol. 64, no. 3

670--693

EN

The study focuses on the characterization of the groundwater salinity on the Nador coastal aquifer (Algeria). The groundwater quality has undergone serious deterioration due to overexploitation. Groundwater samplings were carried out in high and low waters in 2013, in order to study the evolution of groundwater hydrochemistry from the recharge to the coastal area. Different kinds of statistical analysis were made in order to identify the main hydrogeochemical processes occurring in the aquifer and to discriminate between different groups of groundwater. These statistical methods provide a better understanding of the aquifer hydrochemistry, and put in evidence a hydrochemical classification of wells, showing that the area with higher salinity is located close to the coast, in the first two kilometers, where the salinity gradually increases as one approaches the seaside and suggests the groundwater salinization by seawater intrusion.

8

Contribution of a Geographic Information System to Assess the Vulnerability to Groundwater Pollution of the Free Water Table from the Oued Souf Region (South-East Algeria)

67%

Khelfaoui F. , Sayad L. , Attoui B. , Bouselsal B. , Ghezaili S.

|

tom Vol. 31, no. 3

1--17

EN

The Oued Souf free aquifer located in the South East of Algeria represents the main water resource used mostly for urban and agricultural activities. The intensive use of chemical fertilizers has led to serious environmental problems such as contamination of the free aquifer in the region. Thus, aquifer vulnerability has been assessed using several different methods (DRASTIC, GOD, and the Susceptibility Index ‘SI’) based on a geographic information system (GIS). For each method, two vulnerability maps have been developed in the years 2002 and 2012. These maps show that the study area is more exposed to urban, and especially agricultural, pollution. Two classes of vulnerability (moderate and high) have been identified by both DRASTIC and GOD methods. A combined analysis reveals that the moderate class showing 48% (for the GOD method), and the high class showing 57% (for the DRASTIC method) are the most dominant. However, the Susceptibility Index method (SI) revealed that the vulnerability varies from moderate to very high-level classes. In 2012, about of 53% of the study area was dominated by moderate vulnerability classes. The high vulnerability class also includes a considerable part of the land (41%) around urban or strongly agricultural areas, while only 6% is under very high vulnerability groundwater contamination. In addition, a marked decrease in the vulnerability level was noticed in 2012 compared to 2002. This decrease is mainly due to the lowering of the water table after the installation of a vertical drainage network to evacuate the surplus water to the depression and Chotts areas in the North of the region. These results provide a guide for decision-makers involved in the protection of groundwater pollution in such a vulnerable area.

9

Cleanup and valuation of waters of the aquifer of M’zab Valley (Algeria)

67%

Ouled Belkhir C. , Remini B.

Journal of Water and Land Development

|

2016

|

tom no. 29

23--29

EN

The M’zab valley is a hyper arid region of average rainfall not exceeding 100 mm per year. However, the rare floods that occur in M’zab River drain large volumes of surface water. Thanks to the genius of the local population, traditional dams were made for artificial recharge of groundwater. Grace of traditional wells drilled in the valley, farmers irrigate their palm groves and gardens. However, since more than half a century, the contribution of deep drilling for the exploitation of the aquifer of the Continental Intercalary posed environmental problems. On the basis of investigations and surveys of the local population during the years 2010, 2011, 2012 and 2013, it appears that these modern techniques in water catchment caused harmful consequences to the region like the rising of water consumption, pollution of groundwater and soil salinity. Solutions and recommendations are outlined in this article.

PL

Dolina M’zab to suchy region charakteryzujący się niewielką ilością opadów (poniżej 100 mm rocznie) i rzadko zdarzającymi się gwałtownymi powodziami, które niosą ogromne ilości wód. Dzięki zdolnościom miejscowej ludności w dolinie rzecznej powstawały tradycyjne zapory pozwalające uzupełniać zasoby wód podziemnych. Tradycyjne studnie wiercone w dolinie umożliwiają rolnikom nawadnianie gajów palmowych i ogrodów. Jednakże od ponad pół wieku eksploatacja głębokich odwiertów z kredowych warstw wodonośnych stwarza problemy środowiskowe. Na podstawie badań z lat 2010–2013 i ankietowania miejscowej ludności można wysnuć stwierdzenie, że nowoczesne techniki wykorzystywania wody w zlewni rodzą poważne konsekwencje dla regionu w postaci wzrostu zużycia wody, zanieczyszczenia wód gruntowych i zasolenia gleby. W niniejszym artykule przedstawiono rozwiązania i zalecenia w tym zakresie.