Attapulgite as Potential Adsorbent for Dissolved Organic Carbon From Oily Water          下载免费PDF全文

Mansour Al. Haddabi  Hari Vuthaluru  Hussein Znad  Mushtaque Ahmed 《洁净——土壤、空气、水》2015,43(11):1522-1530

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Geospatial and geostatistical approach for groundwater potential zone delineation   总被引：1，自引：0，他引：1       下载免费PDF全文

Javed Mallick  Chander Kumar Singh  Hussein Al‐Wadi  Mohd Ahmed  Atiqur Rahman  Satyanarayan Shashtri  Saumitra Mukherjee 《水文研究》2015,29(3):395-418

Over the past few decades, groundwater has become an essential commodity owing to increased demand as a result of growing population, industrialization, urbanization and so on. The water supply situation is expected to become more severe in the future because of continued unsustainable water use and projected change in hydrometeorological parameters due to climate change. This study is based on the integrated approach of remote sensing, geographical information system and multicriteria decision‐making techniques to determine the most important contributing factors that affect the groundwater resources and to delineate the groundwater potential zones. Ten thematic layers, namely, geomorphology, geology, soil, topographic elevation (digital elevation model), land use/land cover, drainage density, lineament density, proximity of surface water bodies, surface temperature and post‐monsoon groundwater depth, were considered for the present study. These thematic layers were selected for groundwater prospecting based on the literature; discussion with the experts of the Central Ground Water Board, Government of India; field observations; geophysical investigation; and multivariate techniques. The thematic layers and their features were assigned suitable weights on Saaty's scale according to their relative significance for groundwater occurrence. The assigned weights of the layers and their features were normalized by using the analytic hierarchy process and eigenvector method. Finally, the selected thematic maps were integrated using a weighted linear combination method to create the final groundwater potential zone map. The final output map shows different zones of groundwater potential, namely, very good (16%), good (35%), moderate (28%) low (17%) and very low (2.1%). The groundwater potential zone map was finally validated using the discharge and groundwater depth data from 28 and 98 pumping wells, respectively, which showed good correlation. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

The Taratash indenter and its role in the geological structure of the Urals     

Al. V. Tevelev  Ark. V. Tevelev  V. A. Fedorchuk  A. O. Khotylev  I. A. Kosheleva 《Moscow University Geology Bulletin》2017,72(2):95-105

This work presents the results of studying zones bounded by the Archean and Early Proterozoic Taratash block, which breaks the meridional structure of the Urals, pinching its structural zones at the latitude of the town of Miass. The mesostructures of rupture zones, microtextures of tectonites, anisotropy of the magnetic susceptibility, and seismic-wave propagation rate in blastomylonites were studied. The kinematic history of the Taratash block consists of two phases: (1) exhumation in the Middle Riphean under conditions of crustal extension; and (2) the formation of an indenter in the Late Paleozoic under conditions of compression.  相似文献   

Prediction of input energy spectrum: attenuation models and velocity spectrum scaling          下载免费PDF全文

F. S. Alıcı  Halûk Sucuoğlu 《地震工程与结构动力学》2016,45(13):2137-2161

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Mobility of rare earth elements in the system soils–plants–groundwaters: a case study of an arid area (Oman)     

Khadija Semhi  Osman A. E. Abdalla  Salah Al Khirbash  Tabisam Khan  Salim Asaidi  Sardar Farooq 《Arabian Journal of Geosciences》2009,2(2):143-150

Groundwater samples from six wells and various species of plants from soils developed on ophiolites were collected from an arid area (AlKhod area, Oman) and analyzed for trace elements including rare earth elements (REEs). The distribution patterns of REEs in plants indicated an enrichment in middle REEs (MREEs?=?Sm to Dy) and heavy REEs (HREEs?=?Ho to Lu), when they are normalized to the REE composition of the Post Archean Australian Shale (PAAS), with a significant negative anomaly in Ce and a positive anomaly in Eu. Compared to Oman ophiolites, the REEs in different species of plants are depleted in Ce and enriched in MREEs and slightly enriched in light REE (LREE?=?from La to Nd). Relative to PAAS, the distribution of REEs in groundwaters revealed similar patterns to the REE distribution in plants. The distribution patterns of REEs in plants relative to those in waters are nearly flat. These patterns suggest that the transfer of REEs from soil solutions to the groundwaters in Oman occurs without any significant fractionation.  相似文献   

The dynamics of two interacting compositional plumes     

T. B. A. Elbashir  M. A. Al Lawati  I. A. Eltayeb 《地球物理与天体物理流体动力学》2013,107(1):29-63

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Field Evaluation of Arid Soils Wetting Pattern in Subsurface Drip Irrigation Scheme     

Naji K. Al‐Mefleh  Majed Abu‐Zreig 《洁净——土壤、空气、水》2013,41(7):651-656

A field study evaluating wetted radius (Wr), downward depth (Dd), and upward movement (Um) under different emitter discharges and lateral depths was conducted. Four emitter discharges (2, 4, 8, and 16 L/h) and four lateral depths (0, 10, 20, and 30 cm) were tested in a clay loam soil. Relationships were found between the emitter discharge and lateral depth versus Wr, Dd, and Um. Wetting area at the surface occurs under different emitter discharges and lateral depths except at 30 cm lateral depth. At lateral depth of 0 and 10 cm, Wr and emitter discharge were positively correlated. The Dd was not affected by emitter discharge except for laterals installed at 20 cm depth. At 30 cm lateral depth, the correlations between each of Wr, Um, and Dd with emitter discharge were poor. The ratios of Wr/Dd and Um/Dd, with respect to emitter position, were less than unity over different emitter discharges and lateral depths. These results shed some light on the design of subsurface drip irrigation scheme so that the spacing between emitters should be determined based on the lateral depths and discharge of emitters. Evaporation losses were negligible for the 30‐cm‐lateral depth since the upward moisture movement has not reached the soil surface area at all discharge rates tested in the study.  相似文献   

Characterisation of organic matter and microbial communities in contrasting arsenic-rich Holocene and arsenic-poor Pleistocene aquifers,Red River Delta,Vietnam     

Wafa M. Al Lawati  Athanasios Rizoulis  Elisabeth Eiche  Christopher Boothman  David A. Polya  Jonathan R. Lloyd  Michael Berg  Patricio Vasquez-Aguilar  Bart E. van Dongen 《Applied Geochemistry》2012

High concentrations of geogenic As in the groundwaters of south and SE Asia, which are used as drinking waters, are causing severe health impacts to the exposed human populations. It is widely accepted that As mobilisation from sediments into these shallow reducing groundwaters requires active metal-reducing microbes and electron donors such as organic matter (OM). Although OM in such Holocene aquifers has been characterised, there is a dearth of data on Pleistocene aquifers from the same areas. Reported here are preliminary studies of OM and microbial communities present in two aquifers, one of Pleistocene and one of Holocene age, with contrasting concentrations of As (viz. Pleistocene: low As <10 μg/L; Holocene: high As up to 600 μg/L) from Van Phuc village in the Red River Delta, Vietnam. Results revealed OM inputs from multiple sources, including potential contributions from naturally occurring petroleum seeping into the shallow aquifer sediments from deeper thermally mature source rocks. Although concentrations vary, no noticeable systematic differences in biomarker distribution patterns within the OM were observed between the two sites. Microbial analyses did not show a presence of microbial communities previously associated with As mobilisation. All clone libraries were dominated by α-, β-, and γ-Proteobacteria not known to be able to reduce Fe(III) or sorbed As(V). Furthermore, representatives of the Fe(III)-reducing genus Geobacter could only be detected at very low abundance by PCR, using highly selective 16S rRNA gene primers, supporting the hypothesis that metal reduction is not a dominant in situ process in these sediments. No correlation between As concentration in groundwater and OM composition nor microbial community in the host sediments was found. This suggests that either (i) As is not being significantly mobilised in situ in these sediments, instead As appears to be mobilised elsewhere and transported by groundwater flow to the sites or (ii) sorption/desorption processes, as implicated by geochemical data from the cores, play a critical role in controlling As concentrations at these sites.  相似文献   

Pipe Service Age Effect on Chlorine Decay in Drinking‐Water Transmission and Distribution Systems     

A. O. Al‐Jasser 《洁净——土壤、空气、水》2011,39(9):827-832

Maintaining acceptable quality of water transported in the transmission and distribution system requires the chlorination of water beyond the treatment plant. While flowing through pipes, the chlorine concentration decreases for different reasons. Reaction with the pipe material itself and the reaction with both the biofilm and tubercles formed on the pipe wall are known as pipe wall demand. This varies with pipe parameters. The aim of this paper was to assess the impact of the service age of pipes on the chlorine wall decay constant. One hundred and fifty three pipe sections of different sizes and four different pipe materials were collected and tested for their chlorine first‐order wall decay constants. The results showed that pipe service age was an important factor that must not be ignored. For the range of the 55 years of pipe service age used in this study, the change in the wall decay ranged from 8 to 531% of the corresponding values in the recently installed pipes. The effect of service age on the wall decay constants was most evident in steel pipes. Other important findings were reached.  相似文献   

Shkol’noe gold deposit, the Russian Northeast     

A. V. Volkov  N. E. Savva  A. A. Sidorov  V. Yu. Prokof’ev  N. A. Goryachev  S. D. Voznesensky  A. V. Al’shevsky  A. D. Chernova 《Geology of Ore Deposits》2011,53(1):1-26

The Shkol’noe deposit is localized in a small granitoid stock, the root portion of which is traced using geophysical data to a depth of 5–8 km. The high-grade gold ore (33 gpt Au) is enriched in silver and principally differs in ore composition from the previously studied mesothermal gold-quartz and epithermal gold-silver deposits in the Russian Northeast. The main reserves of the Shkol’noe deposit concentrate in bonanzas (20% of the total volume of orebodies). The internal deformation is related to the rearrangement of matter in freibergite; exsolution structures in fahlore and native gold are related to postmineral metamorphism. It is suggested that the ore of the Shkol’noe deposit occupies a transitional position between porphyrytype and epithermal levels of ore deposition.  相似文献