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1.
This preliminary work reported here dealt with potential impacts of wastewater irrigation on soils and crops sampled along the Koshk River canal in the suburban area of Shiraz City, Iran. It also attempts to assess the extent of heavy metal contamination in soils and crops and human exposure risk. For this purpose, samples including soils and plants were collected from two wastewater irrigated sites and a tubewell-irrigated site (marked by A, B and C). Concentrations of the six heavy metals Ni, Pb, Cd, Zn, Cr and Cu were determined by AAS. Physical and chemical properties of soil samples were also determined. The PLIs and CF for soils and HQ (Hazard quotient) for some vegetables were calculated. The results showed that organic matter content increased from 22% to 30 % in wastewater-irrigated soils as compared to tubewell water irrigated and admixture water irrigated ones. The soil pH was raised by 2 units as a result of wastewater irrigation at site A compared to sites B and C. Wastewater irrigation also result in relatively high concentrations of Ni, Pb and Zn (275.5, 441.3 and 177 mg/kg, respectively) in wastewater irrigated soils over tubewell water irrigated soils. These levels are higher than the maximum permissible limits in unpolluted soils, indicating that a degree of contamination has occurred. This was confirmed by calculated PLIs and contamination factors in soil samples, The results also showed some crops cultivated at sites A and B contained high levels of Ni and Cd beyond the maximum permissible concentrations and those cultivated at site C. The concentrations of these heavy metals are within or very close to the critical levels. HQ indices and daily intake calculated in respect of metal contents in some vegetables (spinach, lettuce and celery) showed that toxic risk due to Cd in these vegetables and crops was greater than one. This study generally concludes that although the content of heavy metals did not reach toxic level, extensive use of untreated wastewater drawn from the Koshk River has obviously increased the contamination of Ni and Pb in soils and Cd in some vegetables cultivated along the canal, causing potential health risk in the long-term scense for consumers or local residents.  相似文献   

2.
Groundwater contamination is one of the most significant problems in arid countries. Al-Quwiy’yia region is an example of an area where the groundwater is contaminated as a result of infiltration of waste water in low-lying areas adjacent to inhabited zones. Such contamination poses significant environmental threats for the surrounding environment and groundwater. Surface observations and spatial distribution of contamination observed in the shallow aquifer indicate that the main contamination sources were from sewage as well as from waste water dumping. However, the main source of water supply for the whole area is groundwater abstracted from the relatively shallow aquifer. Therefore, the transient electromagnetic method (TEM) and 2D electrical resistivity tomography (2D ERT) have been applied close to the waste water dump site to characterize the response of pollution plumes. Both of these geoelectrical techniques are sensitive to electrical conductivity as well as to other physical properties, which are greatly influenced by the polluted groundwater. Therefore, it is possible to profile the contamination plumes, both vertically and horizontally, in the vicinity of the measured stations. The ERT profiles gave detailed information about the lateral distribution of the contaminated groundwater, whereas the TEM demonstrated the vertical extensions.  相似文献   

3.
Pham  Quoc Bao  Ali  Sk Ajim  Bielecka  Elzbieta  Calka  Beata  Orych  Agata  Parvin  Farhana  Łupikasza  Ewa 《Natural Hazards》2022,113(2):1043-1081
Natural Hazards - Advances in the availability of multi-sensor, remote sensing-derived datasets, and machine learning algorithms can now provide an unprecedented possibility to predict flood events...  相似文献   

4.
Controlled by E-W-trending faults, a Proterozoic (1.4-1.8 Ga old) rapakivi granite suite was intruded inBeijing and the area to its east (within Hebei Province), forming three parallel belts of igneous rocks. Theisotopic, trace element and rare earth element geochemical data of a bimodal rock association made up ofanorthosite, gabbro and alkali basalt and olivine-bearing quartz-syenite, rapakivi granite and trachyte as wellas potassic A-type granites and anorogenic granites—— all suggest that there exists an incipient rift in thestudy area. Fractional crystallization of a mixed magma formed by the magma derived from the upper mantleand the magma derived by small degrees of fusion of the lower crust produced anorthosite cumulates. Thewater-deficient granitic magma was differentiated into a subalkaline series. When the fractional crystallizationwas incomplete, rhythmic eruptions took place.  相似文献   

5.
The Takab area in NW of Iran is an important gold mineralized region with a long history of gold mining. In this study ASTER data is used to evaluate environmental effects of gold mining. The results show that mining activities have resulted in release of…  相似文献   

6.
Natural Hazards - A hazard map is a map which shows about all the vulnerable regions present in any country or at any specific place or location which is affected or will be affected by natural...  相似文献   

7.
INTRODUCTIONManystudiesofglobalchangesshowthatthehydrologicalcycleofacontinentalscalecanberelatedtoclimaticchanges(Andersonetal.,2 0 0 1;KarenandDara,2 0 0 1;MichaelandMichael,1999;Hugoetal.,1996 ;Larryetal.,1996 ) .Cur rentdistributionpatternsofdeuteriumandoxygen 18concen …  相似文献   

8.
Guangdong is the most economically developed province in China, which is a large CO2 emitter and hence is faced with severe carbon reduction pressures. In this paper, a cost assessment methodology based on scenario analysis is presented. A CO2 source and sink database was built at Guangdong after detailed investigations on the point sources and sedimentary basins. Fifteen transport and five storage scenarios were defined and studied, respectively. Cost estimates based on these scenarios show that during its lifetime, the costs of both transport and storage depend on the amount of CO2 processed. More CO2 being processed will bring down the unit costs of both transport and storage. However, it was observed that there is a cost inflection point between the storage amount of 35.2 and 52.8 Mt/year, which means that as the storage amount increases, the storage cost will first decrease and then increase. Source region S1 in Guangdong has been recommended for an early chance of CO2 storage. Preliminary cost comparisons have shown that the results presented in this study are reasonable, but to improve the cost assessment accuracy of offshore CO2 storage, a methodology based on a CO2 storage design that can integrate local prices needs to be further developed.  相似文献   

9.
A catastrophic landslide following a rainy season occurred in the backyard of a school building in Söke, Turkey. The landslide caused property damage and adversely affected the present forest cover. Immediately after the landslide, double-row stabilizing piles were designed and constructed based on the findings of two-dimensional (2D) finite element (FE) analyses to take an urgent precaution. To remedy the problem, pile displacements were monitored using inclinometers, and it was observed that the measured displacements were greater than the values calculated in the design stage. Accordingly, two different three-dimensional (3D) numerical FE models were used in tandem with the inclinometer data to determine the load transfer mechanism. In the first model, numerical analyses were made to predict the pile displacements, and while the model predicted successfully the displacement of the piles constructed in the middle with reasonable accuracy, it failed for the corner piles. In the second model, the soil load transfer between piles was determined considering the sliding mass geometry, the soil arching mechanism and the group interaction between adjacent piles. The results of the second model revealed that the middle piles with large displacements transferred their loads to the corner piles with smaller displacements. The generated soil loads, perpendicular to the sliding direction, restricted pile deformations and piles with less displacement were subjected to greater loads due to the bowl-shaped landslide. A good agreement between the computed pile displacements and inclinometer data indicates that the existing soil pressure theories should be improved considering the position of the pile in the sliding mass, the depth and deformation modulus of stationary soil, the relative movement between the soil and piles and the relative movement of adjacent piles.  相似文献   

10.
In the “Sea Diamond” shipwreck, it is estimated that almost 1.7 tons of batteries/accumulators and approximately 150 cathode ray tube technology televisions have gone to the bottom of the sea. Under these circumstances, all the aforementioned materials will eventually undergo severe accelerated corrosion. Consequently, a variety of heavy metals will either be released in seawater or precipitate in the form of salts resulting in contamination of the sea sediments. According to the ship data, and the aforementioned quantities of batteries and televisions, it is estimated that approximately 75–80 g of mercury, 630–1,050 g of cadmium and 1.14–1.26 tons of lead exist in the wreck only due to the electrical and electronic equipment present in the ship, not to mention the significant amount of heavy metals such as copper, nickel, ferrous and chromium that exist in the hulk. Four series of seawater sampling (n = 85) were conducted in different stations surrounding the wreck area in order to assess the overall impact from the release of heavy metals in the surrounding aquatic environment. The analysis indicated that there were stations where lead, zinc and cadmium were present in concentrations higher than the permissible limits set by the Unites States Environmental Protection Agency for seawater. Furthermore, the analysis of three series of sediment sampling (n = 31) from the wreck area showed elevated but expected concentration values for ferrous and manganese, considering the geological background of the area and contamination with lead, copper and cadmium.  相似文献   

11.
Landslide hazard or susceptibility assessment is based on the selection of relevant factors which play a role on the slope instability, and it is assumed that landslides will occur at similar conditions to those in the past. The selected statistical method compares parametric maps with the landslide inventory map, and results are then extrapolated to the entire evaluated territory with a final product of landslide hazard or susceptibility map. Elements at risk are defined and analyzed in relation with landslide hazard, and their vulnerability is thus established. The landslide risk map presents risk scenarios and expected financial losses caused by landslides, and it utilizes prognoses and analyses arising from the landslide hazard map. However, especially the risk scenarios for future in a selected area have a significant importance, the literature generally consists of the landslide susceptibility assessment and papers which attempt to assess and construct the map of the landslide risk are not prevail. In the paper presented herein, landslide hazard and risk assessment using bivariate statistical analysis was applied in the landslide area between Hlohovec and Sered?? cities in the south-western Slovakia, and methodology for the risk assessment was explained in detail.  相似文献   

12.
This study presents the data on the hydrochemical characteristics and isotope chemistry of Liwa aquifer, which could be useful to clarify the hydrochemical facies and hydrogeological regime in the study area. Electric conductivity and total dissolved solid values show that the investigated water is slightly brackish, due to the effect of evaporation and the occurrences of evaporite rocks in the adjacent Sabkhas of Abu Dhabi. Major cations and anions arranged according to their decreasing concentrations are: Na+ > Ca+2 > K+ > Mg+2 and Cl > HCO3  > SO4−2, respectively. As sodium is the dominate cation and chloride is the prevailing anion, hydrochemically the groundwater of Liwa can be classified as Na–Cl rich, predominantly chloridic. Ion concentrations increase towards the northeast and presumably coincide with the lithological sources of ions. Factors affecting the hydrochemistry of the groundwater of the investigated area include the effect of weathering of soil and rocks, evaporation and agricultural activities. Stable isotopes of oxygen and hydrogen show that the shallow aquifers contain a single water type that originated in a distinct climatic regime. This water type deviates from the local meteoric water line, as well as from the Eastern Mediterranean Meteoric Water Line, suggesting potential evaporation of recharged water prior to infiltration. The waters are poor in tritium, and thus can be considered generally as indication for recharge prior to 1952. The degradation of groundwater quality can be attributed to evaporation and agricultural practices in most cases.  相似文献   

13.
Groundwater conditions in a 75- km2 coastal area around the town of Telde in eastern Gran Canaria island have been studied. Pliocene to Recent volcanic materials are found, with an intercalated detrital formation (LPDF), which is a characteristic of the area. Groundwater development has become intensive since the 1950s, mostly for intensive agricultural irrigation and municipal water supply. The LPDF is one order of magnitude more transmissive and permeable than the underlying Phonolitic Formation when median values are compared (150 and 15 m2 day–1; 5 and 0.5 m day–1, respectively). These two formations are highly heterogeneous and the ranges of expected well productivities partly overlap. The overlying recent basalts constituted a good aquifer several decades ago but now are mostly drained, except in the southern areas. Average values of drainable porosity (specific yield) seem to be about 0.03 to 0.04, or higher. Groundwater development has produced a conspicuous strip where the watertable has been drawn down as much as 40 m in 20 years, although the inland watertable elevation is much less affected. Groundwater reserve depletion contributes only about 5% of abstracted water, and more than 60% of this is transmitted from inland areas. Groundwater discharge into the sea may still be significant, perhaps 30% of total inflow to the area is discharged to the sea although this value is very uncertain.
Resumen Se ha llevado a cabo un estudio detallado de una zona costera de 75 km2 situada en la costa del Municipio de Telde, al Este de la isla de Gran Canaria, en el Archipiélago Canario. En ella se encuentran materiales volcánicos de edad Pliocena a Reciente, con una formación detrítica intercalada (FDLP), que constituye la máxima singularidad del área. La explotación de las aguas subterráneas ha sido intensiva a partir de la década de 1950, fundamentalmente para el riego de cultivos intensivos y para el suministro a la población. Comparando las medianas de los valores de transmisividad y permeabilidad entre la FDLP y la Formación Fonolítica que está debajo (140 a 15 m2/día y 5 a 0,5 m/día respectivamente) se comprueba que la primera es un orden de magnitud más transmisiva y permeable que la segunda, aunque ambas formaciones son muy heterogéneas y los rangos de productividad esperables en los pozos se solapan entre sí. Los Basaltos Recientes que están encima fueron un buen acuífero hace algunas décadas, pero en la actualidad han sido drenados casi en su totalidad, excepto en el sector Sur. Los valores medios de la porosidad drenable (eficaz) parecen estar alrededor de 0,03 a 0,04, o más. La explotación de las aguas subterráneas ha producido una franja con un destacado descenso de los niveles piezométricos, que alcanza los 40 m en 20 años, aunque la superficie piezométrica hacia el centro de la isla está menos afectada. El descenso calculado en la reserva de aguas subterráneas alcanza solamente un 5% del agua extraída y más de un 60% se transmite desde las cumbres de la isla. La descarga al mar puede ser aún significativa, quizás el 30% de las entradas totales, aunque esta cifra es muy incierta.

Résumé Les conditions de gisement de leau souterraine dune région de 75 km2 de la côte Est de lîle de la Grande Canarie (archipel des Canaries), dans le secteur de Telde, ont été étudiées, en utilisant seulement les données fournies par les puits dexploitation existants. Les matériaux volcaniques, dâge Pliocène à sub-actuel, sont séparés par une formation détritique (FDLP), qui constitue la principale singularité de cette région. Lexploitation de leau souterraine est devenue intensive à partir de 1950, principalement pour des besoins dirrigation (agriculture intensive) et dalimentation en eau des zones urbaines. La comparaison des valeurs médianes montre que la FDLP est dun ordre de grandeur plus transmissive et perméable que les formations volcaniques phonolitiques au-dessous (respectivement 150 et 15 m2/jour ; 5 et 0,5 m/jour). Néanmoins, ces deux formations sont très hétérogènes et les deux gammes de valeurs de productivité des puits se recouvrent. Les Basaltes récents au-dessus qui constituaient, il y a encore quelques décades, un bon aquifère, sont presque entièrement desaturés à lheure actuelle, a exception faite de la partie sud. Les valeurs moyennes de porosité drainable (efficace) sont de lordre de 0,03 à 0,04, voire localement plus élevées. Lexploitation des eaux souterraines a induit de forts rebattements au long dune zone littorale (denviron 40 m au cours des 20 dernières années), alors que la surface piézométrique est moins affectée en amont vers le centre de lîle. La diminution de la réserve des eaux souterraines dans la zone étudiée représente seulement 5% des volumes deau extraits. Plus de 60% proviennent du centre de lîle. Les écoulements vers la mer peuvent être significatifs, (environ 30% des entrées totales) bien que cette estimation soit sujeté à une très forte incertitude.
  相似文献   

14.
The National Virtual Core Library (NVCL) HyLogging core-scanning system generates mineralogical information from visible, short-wave infrared and thermal infrared spectroscopic data. Currently, HyLogging data are freely available for more than 1500 drill holes via the AuScope Discovery Portal and various Geological Survey websites. With any new technology, there is commonly a lag between provision and take-up by users that can be aided by the publication of case studies in the scientific literature. This paper uses the Mt Davies nickel–cobalt (Ni–Co) laterite deposits, located in northwest South Australia, as a case study to assess the accessibility and representation of HyLogger data and provides an example of its application to all aspects of resource mining: exploration, extraction and processing, and remediation. In this study, we combine HyLogger-derived scalars indicating Fe-oxide and clay mineralogy with historical geological logs and assay data. In general, background Ni grades (<0.1 wt%) are linked to the presence of montmorillonite + hematite ± goethite, moderate grades (0.1–1.0 wt%) are associated with goethite ± nontronite ± saponite ± kaolinite ± montmorillonite, and higher grades (1.0–2.0 wt%) are coincident with goethite and minimal clay alteration, suggesting that goethite hosts Ni mineralisation. Gibbsite, where it occurs, is found immediately above zones of moderate to high Ni grades and may be an important proximal indicator mineral of nickeliferous laterite. Such a case study serves to suggest opportunities for further data modelling and search and query functionality that could facilitate increased use of this important digital geoscience data resource by the Australian minerals industry for all aspects of resource exploitation: exploration, extraction, processing, and environmental remediation.  相似文献   

15.
A holistic study of the composition of the basalt groundwaters of the Atherton Tablelands region in Queensland, Australia was undertaken to elucidate possible mechanisms for the evolution of these very low salinity, silica- and bicarbonate-rich groundwaters. It is proposed that aluminosilicate mineral weathering is the major contributing process to the overall composition of the basalt groundwaters. The groundwaters approach equilibrium with respect to the primary minerals with increasing pH and are mostly in equilibrium with the major secondary minerals (kaolinite and smectite), and other secondary phases such as goethite, hematite, and gibbsite, which are common accessory minerals in the Atherton basalts. The mineralogy of the basalt rocks, which has been examined using X-ray diffraction and whole rock geochemistry methods, supports the proposed model for the hydrogeochemical evolution of these groundwaters: precipitation + CO2 (atmospheric + soil) + pyroxene + feldspars + olivine yields H4SiO4, HCO3 , Mg2+, Na+, Ca2+ + kaolinite and smectite clays + amorphous or crystalline silica + accessory minerals (hematite, goethite, gibbsite, carbonates, zeolites, and pyrite). The variations in the mineralogical content of these basalts also provide insights into the controls on groundwater storage and movement in this aquifer system. The fresh and weathered vesicular basalts are considered to be important in terms of zones of groundwater occurrence, while the fractures in the massive basalt are important pathways for groundwater movement.  相似文献   

16.
Ian Carmichael spent 45 years thinking about and working on the activities of components in silicate melts and their use to estimate physicochemical conditions at eruption and in the source regions of igneous rocks. These interests, principally in major components such as SiO2, led us to think about possible ways of determining the complementary activity coefficients of trace components in silicate melts. While investigating the conditions of accretion and differentiation of the Earth, a number of authors have determined the partitioning of trace elements such as Co, Ni, Mo and W between liquid Fe metal and liquid silicate. These data have the potential to provide activity information for a large number of trace components in silicate melts. In order to turn the partitioning measurements into activities, however, we need to know the activity coefficient of FeO, γFeO in the silicate. We obtained γFeO as a function of melt composition by fitting a simple model to 83 experimental data for which the authors had measured the FeO content of the silicate melt in equilibrium with metal (Fe-bearing alloy) at known fO2. The compositional dependence of γFeO is weak, but, when calculated in the system Diopside–Anorthite–Forsterite, it decreases towards the Forsterite apex. A similar approach for Ni, for which twice as many data are available, leads to similar composition dependence of activity coefficient and confirms the suggestion that γNiOFeO is almost constant over a wide range of silicate melt composition. The activity coefficients for FeO were used in conjunction with measured Mo and W partitioning between Fe-rich metal and silicate melt to estimate activity coefficients for trace MoO2 and WO3 dissolved in silicate melt. When combined with data on Mo- and W-saturated silicate melts a strong dependence of activity coefficient is observed. Calculated in the system Diopside–Anorthite–Forsterite, both MoO2 and WO3 exhibit similar behaviour to FeO and NiO in that activity coefficients decrease as Forsterite content increases. The effect is much larger for Mo and W, however, γMoO2 and γWO3 varying by factors of 20 and nearly 100, respectively, in this system. In order to illustrate the potential applications of the metal–silicate partitioning approach to determine the activity coefficients of volatile elements, we used it to determine activity coefficients of PbO, CuO0.5 and InO1.5 in a silica-saturated melt at 1,650 °C. We find values of 0.22, 3.5 and 0.02, respectively, indicating a strong dependence on cation charge. The value for CuO0.5 is in excellent agreement with experimental data of Holzheid and Lodders (Geochim Cosmochim Acta 65:1933–1951, 2001), which shows that the method is viable. When combined with thermodynamic data on the gas species, we find that Pb is the most volatile of the 3 elements under ‘normal’ terrestrial conditions of oxygen fugacity but that In should become the most volatile under strongly reducing conditions such as those of the solar nebula. The oxygen fugacity dependence of volatility has implications for the high relative abundance of In in silicate Earth. We conclude that metal–silicate partitioning experiments are a viable means for determining activities of trace components in silicate melts and are particularly useful if the metal of the element is unstable or volatile at igneous temperatures.  相似文献   

17.
During the last century, several lead mines and a metal smelter were in production in the Upper Ribeira Valley, southeastern Brazil. After fifty years of activity, the refinery was shut down in November 1995 and, thereafter the last mines in production were closed. Since 1998, a multidisciplinary research group has carried out an ambitious investigation among the population of five municipalities in the Ribeira Valley (sampled population of 472 children and 523 adults) to assess the human exposure to lead. The highest blood lead levels were found among the population of two villages in the vicinity of the smelter where soil and indoor-dust are highly contaminated. During the present study, the lead contents of several food species that are part of local population diet were investigated. Greens, vegetables, corn, chicken eggs and cow milk, were sampled in two occasions, July 2004 and February 2005. The analytical procedures included burning of organic matter, pre-concentration of lead and, finally, determination by AAS using background correction. The quantification limit was 0.05 μg/g Pb. Soil samples were also collected and analyzed by X-ray fluorescence spectroscopy with a quantification limit of 2 μg/g Pb. The results are very impressing since 100% of greens, vegetables and eggs yielded lead concentrations exceeding the upper limits established by Brazilian regulations whereas milk and maize samples presented lead contents below the regulated limit of 0.05 μg/g Pb. Lead concentrations in soil varied between 156 and 1292 μg/g Pb, resembling the results of previous studies and far exceeding the threshold of 200 μg/g Pb indicated as the intervention value. Lead contents in some species vary consistently with lead concentrations in soils, however, other factors may account for the bioavailability of lead and its intake by plants, like the soil pH, its cationic exchange capacity, clay and organic matter contents, characteristics of the plant species itself, climate, among others.  相似文献   

18.
INTRODUCTIONThermalgroundwaterisfoundtohaveoccurredinthebedrockcarbonateaquifersofLowerPaleozoicandMeso toNeo ProterozoicErathemsnearTianjin ,China .Thebedrockaquifersexistinthelayersbetweenabout 10 0 0mandmorethan 4 0 0 0mbelowthelandsurface .Thethermalwaterhasbeensuccessfullydevelopedoverthepast2 0yearstoprovideasourceofhotwaterforavarietyofresidentialandindustri alpurposes.Geothermalwellstappingtheaquifersarecapa bleofproducingcommercialquantitiesofhotwaterwiththetemperaturesranging…  相似文献   

19.
This work was carried out in order to study the impact of car body repair activities in Bouzaréah City (suburban area located at the plateau of Algiers) on the air quality. Atmospheric particulate matter was targeted using high-volume sampler. Precisely, the particulate organic matter such as organophosphate esters, especially triphenyl phosphate and tributyl phosphate, was evaluated by the implementation of accelerated solvent extraction. The results of the major extractable organic components revealed that tributyl phosphate and triphenyl phosphate were found at 5.46 and 1.78 ng m?3, respectively. On the other hand, the classical pollutants such as n-alkanes, n-alkanoic monocarboxylic acids and polycyclic aromatic hydrocarbons were also measured, respectively, at average total concentrations of 35.8, 107.4 and 9.8 ng m?3. This work confirms that sanding and painting car bodies may contribute to air pollution, especially after detection of diethylnitrosamine which remains the most surprising compound in the particulate matter due to its volatility and can be considered as emerging contaminant.  相似文献   

20.
The present study is an attempt to assess the impact of a saline waste lagoon on the near subsurface through electrical resistivity tomography (ERT). Resistivity and IP imaging data have been collected on profiles close to the lagoon and at a far off location (control location). Water samples have been collected from the lagoon and a municipality drinking well close to it and analysed for the water chemistry. The geoelectrical sections indicate very low resistivity formations in the near subsurface in the vicinity of the lagoon as compared to the control profile. The water chemistry data from the monitoring well close to the profile also indicates very high total dissolved solids (8658 mg/L) and qualitatively supports the contamination of the near subsurface. The conductive formations in the vicinity of the lagoon can be attributed to the overflow from the lagoon or the seepage.  相似文献   

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