Geosciences
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 PHYSICAL SPATIAL DEVELOPMENT: A GIS ANALYSIS WITH EMPHASIS ON ENVIRONMENTAL IMPACTS-CASE STUDY NALOS
作者  Naghibi, F. & Shirmohammadi, H.
作者单位  
期刊  Iranian Journal of Environmental Health Science and Engineering 卷期  Vol. 5, No. 1, 2008 时间  2010.08.11
关键词  GIS, planning, environmental impact, modeling, physical development
摘要   Unplanned urban developments have led to changes in uncontrollable urban spatial structure. For this reasons, informed guidance, principle organization and spatial planning are necessary for urban sprawl and development. In this research, different forms of urban development were considered and development basic barriers including rivers, topography, geology, ecological conditions, facilities andindustries were determined and the role of each one was surveyed. Development trends that are based on effective parameters especially environmental impacts were modeled with Geographic Information Systems. The quality of urban planning and management can be upgraded when available and valid data are handled in an advanced manner with the aid of Geographic Information Systems. The innovative technology can support planning and decision making by offering relatively quick response on analytical questions and monitoring issues. Experienced expert determined the degree and primacy of urban sprawl and development parameters generally and for nalos case study, these parameters and criteria and their weights were marked, then were modeled with Geographic Information Systems for nalos developments. With using GIS and it capabilities in calculation of land size forecasting for Nalos development and its positioning we could take a step in planning directions such as sustainable development achievements.
 Investigation on potential groundwater impacts and influence of local hydrogeology on natural attenu
作者  Longe, E. O. & Enekwechi, L. O.
作者单位  
期刊  International Journal of Environment Science and Technology 卷期  Vol. 4, No. 1, 2007 时间  2010.06.25
关键词  Landfill, natural attenuation, migration,leachate, hydrogeology
摘要   The influence of local hydrogeology on natural attenuation of contaminants from landfill leachates in shallow aquifer underlying the active Olusosun landfill base in Lagos was investigated. In addition, the level of groundwater contamination in the vicinity of the landfill and of leachate migration pattern in groundwater down gradient of the landfill base was equally assessed. Landfill leachate and groundwater samples were collected and analyzed and characterized. Physico-chemical analyses of sampled water followed standard analytical methods. Analytical results showed a measurable impact of leachate outflows on groundwater quality. Elevated levels of anions: nitrate, chloride and sulphate in the groundwater body and heavy metals: Cr3, Cd and Cu, were detected at measurable levels in groundwater down gradient of the landfill location without any particular attenuation pattern. The migration pattern and dispersion of leachates down gradient, 750 m away from the landfill location are irregular and difficult to predict as depicted by levels of contaminants present in groundwater. The study highlighted the importance of soil stratigraphy beneath the landfill base as an important factor in the natural attenuation of leachate constituents in the groundwater body.
 Nitrate, Arsenic and Selenium Concentrations in The Pecos Valley Aquifer, West Texas,USA
作者  Hudak, P. F.
作者单位  
期刊  International Journal of Environmental Research 卷期  Vol. 4, No. 2, 2010 时间  2010.06.10
关键词  Nitrate, Arsenic, Selenium, Groundwater, Texas
摘要   Nitrate, arsenic, and selenium concentrations in the Pecos Valley Aquifer of west Texas were compiled, mapped, and analyzed in the context of local geology and land use. Alluvial deposits of sand, silt, clay, and gravel compose the unconfined aquifer. Ranching and farming are predominant land uses in the rural study area. Data were tabulated from 79 water wells with a median depth of 75 m and mapped with a geographic information system (GIS). The wells were sampled between the years 2003 and 2008. Total dissolved solids (TDS) concentrations in the aquifer were very high, with a median value of 2,687 mg/L. Approximately 18% of observations exceeded the 44.27 mg/L drinking water standard for nitrate, whereas 6% exceeded the 10 μg/L standard for arsenic, and only 4% surpassed the 50 μg/L standard for selenium. There was a statistically significant, direct correlation between arsenic and selenium, as well as between nitrate and selenium concentrations. Moreover, arsenic and selenium concentrations were significantly higher in shallower wells. Probable sources of groundwater contamination in the study area include natural (geological) sources and agricultural activity.
 Physico-chemical and Mineralogical Characterisation of Subsurface Sediments around Gaborone Landfill
作者  NGOLE, V M;TOTOLO, O;EKOSSE, G E
作者单位  
期刊  Journal of Applied Sciences and Environmental Management 卷期  Vol. 8, No. 1, 2004 时间  2010.04.12
关键词  
摘要   Studies were carried out on subsurface sediments obtained around the Gaborone landfill area Botswana, in order to characterize their mineralogy and physico-chemistry, appraise any contaminant inputs from the landfill and assess their ability to attenuate contaminants from the landfill. Physico-chemical properties investigated included particle size distribution (PSD), moisture content, bulk density (Db), porosity, surface area, pH, electrical conductivity (EC), and cation exchange capacity (CEC). The mineral phases occurring in the subsurface sediments were identified by use of X-ray powder diffraction (XRPD) technique. Grain size analyses of the subsurface sediments revealed sandy loam, silty loam, and silt as the main textural classes. The values obtained for Dband porosity is reflective of the textural classes of the different samples. Moisture content values of the studied samples are characteristic of sediments in semi-arid environments. Apart from two samples, which were acidic, others were alkaline. The EC values were indicative of significant amounts of total dissolved salts (TDS) especially along the eastern corner of the landfill. Cation exchange capacity values were relatively low. Minerals identified by XRPD included quartz, microcline, muscovite and kaolinite in bulk subsurface sediments, whereas kaolinite, smectite and /or illite occurred in the clay fractions. Sediment pH, EC and TDS suggests inputs from the landfill. The sediments seem to have a low attenuation capacity as a result of their physico-chemical and mineralogical properties. Further geophysical and hydrogeochemical research is needed to verify if the Gaborone landfill area is environmentally safe.@JASEM
 Physico-chemical and Mineralogical Characterisation of Subsurface Sediments around Gaborone Landfill
作者  NGOLE, V M;TOTOLO, O;EKOSSE, G E
作者单位  
期刊  Journal of Applied Sciences and Environmental Management 卷期  Vol. 8, No. 1, 2004 时间  2010.04.12
关键词  
摘要   Studies were carried out on subsurface sediments obtained around the Gaborone landfill area Botswana, in order to characterize their mineralogy and physico-chemistry, appraise any contaminant inputs from the landfill and assess their ability to attenuate contaminants from the landfill. Physico-chemical properties investigated included particle size distribution (PSD), moisture content, bulk density (Db), porosity, surface area, pH, electrical conductivity (EC), and cation exchange capacity (CEC). The mineral phases occurring in the subsurface sediments were identified by use of X-ray powder diffraction (XRPD) technique. Grain size analyses of the subsurface sediments revealed sandy loam, silty loam, and silt as the main textural classes. The values obtained for Dband porosity is reflective of the textural classes of the different samples. Moisture content values of the studied samples are characteristic of sediments in semi-arid environments. Apart from two samples, which were acidic, others were alkaline. The EC values were indicative of significant amounts of total dissolved salts (TDS) especially along the eastern corner of the landfill. Cation exchange capacity values were relatively low. Minerals identified by XRPD included quartz, microcline, muscovite and kaolinite in bulk subsurface sediments, whereas kaolinite, smectite and /or illite occurred in the clay fractions. Sediment pH, EC and TDS suggests inputs from the landfill. The sediments seem to have a low attenuation capacity as a result of their physico-chemical and mineralogical properties. Further geophysical and hydrogeochemical research is needed to verify if the Gaborone landfill area is environmentally safe.@JASEM
 Physico-chemical and Mineralogical Characterisation of Subsurface Sediments around Gaborone Landfill
作者  NGOLE, V M;TOTOLO, O;EKOSSE, G E
作者单位  
期刊  Journal of Applied Sciences and Environmental Management 卷期  Vol. 8, No. 1, 2004 时间  2010.04.12
关键词  
摘要   Studies were carried out on subsurface sediments obtained around the Gaborone landfill area Botswana, in order to characterize their mineralogy and physico-chemistry, appraise any contaminant inputs from the landfill and assess their ability to attenuate contaminants from the landfill. Physico-chemical properties investigated included particle size distribution (PSD), moisture content, bulk density (Db), porosity, surface area, pH, electrical conductivity (EC), and cation exchange capacity (CEC). The mineral phases occurring in the subsurface sediments were identified by use of X-ray powder diffraction (XRPD) technique. Grain size analyses of the subsurface sediments revealed sandy loam, silty loam, and silt as the main textural classes. The values obtained for Dband porosity is reflective of the textural classes of the different samples. Moisture content values of the studied samples are characteristic of sediments in semi-arid environments. Apart from two samples, which were acidic, others were alkaline. The EC values were indicative of significant amounts of total dissolved salts (TDS) especially along the eastern corner of the landfill. Cation exchange capacity values were relatively low. Minerals identified by XRPD included quartz, microcline, muscovite and kaolinite in bulk subsurface sediments, whereas kaolinite, smectite and /or illite occurred in the clay fractions. Sediment pH, EC and TDS suggests inputs from the landfill. The sediments seem to have a low attenuation capacity as a result of their physico-chemical and mineralogical properties. Further geophysical and hydrogeochemical research is needed to verify if the Gaborone landfill area is environmentally safe.@JASEM
 Soil Heavy Metal Concentration Patterns at Two Speed Zones along the Gaborone-Tlokweng Border Post H
作者  MOHAMMED SHAIKH, NKOBI MOLEELE, GEORGES-IVO E. EKOSSE, OTLOGETSWE TOTOLO, JULIUS ATLHOPHENG
作者单位  
期刊  Journal of Applied Sciences and Environmental Management 卷期  Vol. 10, No. 2, 2005 时间  2010.03.19
关键词  
摘要   Since 1988 Botswana has been experiencing an unprecedented increase in vehicular traffic which is suspected to be having contamination effects on soils along heavily used roads in the country. This study aimed at understanding the contamination trends of heavy metals on soils due to vehicular emissions. The soil physico-chemistry (bulk density, particle size distribution, pH, electrical conductivity and cation exchange capacity), mineralogy (using x-ray diffraction techniques) and heavy metals (Cd, Pb, Cu and Zn) concentrations were determined for soil samples obtained along the roadside at 2m, 4m, 6m and 100 m of the Gaborone - Tlokweng Emigration/Immigration Boarder Post Road, which is one of the busiest in the country. Bulk density of soil samples were from 1.19 to 1.4; and sand, loamy sand and sandy loam textural classes constituted the soil samples. The soil pH was from 5.09 to 8.57; the EC ranged from 6.27 μS cm-1to 20.3 27 μS cm-1and the CEC values were from 10.2 meq100g-1to 27.2 meq100g-1. Clay minerals were identified in the samples as well as feldspar and quartz. The concentration levels for Pb were from 0 mgkg-1to 71 mgkg-1; Zn were from 5.23 mgkg-1to 51.26 mgkg-1; Cu were from 0.3 mgkg-1to 18.1 mgkg-1and Cd 0 mgkg-1to 2.4 mgkg-1. The interplay of soil physico-chemistry and mineralogy on heavy metals concentrations is discussed. Although levels of heavy metals concentrations fell below normal ranges, the values obtained were generally higher than those from some developed and developing countries. @JASEM
 Chemical, Physical, Mineralogical, Morphology and Leaching Characteristics of a Thermal Power Plant
作者  Saeedi, M., Amini, H. R.
作者单位  
期刊  International Journal of Environmental Research 卷期  Vol. 1, No. 1, 2007 时间  2010.01.05
关键词  Power plant, Waste, Heavy metals, Leaching test, Characterization
摘要   Most of electricity is generated by thermal power plants in Iran. Shahid Rajaee thermal power plant consists of four 250MW natural gas and fuel oil burning units that is located at 100 km west off Tehran. As a result of fuel oil burning in winter time, boilers air heaters are washed and cleaned frequently. The wastewater originating from air heater washing contains suspended solids and different dissolved heavy metals particularly V, Ni, Zn, Cr, Pb. Wastewater is then treated in effluent treatment plant by chemical precipitation followed by centrifugal dewatering of sludge. Waste from this process contains significant amounts of heavy metals and is considered as specific industrial wastes that should be more characterized under specific wastes act of Iran. For the first time in Iran, in the present investigation seven composite samples from air heater washing wastewater treatment dewatered sludge were subjected to chemical composition, mineralogy and leaching characteristics studies to better understand the physical and chemical characteristics of this kind of wastes. Regarding fuel oil constituents and environmental impacts of metals the most likely pollutants which would be of concern in this study were heavy metals (Cd, Co, Cr, Mn, Ni, Pb, Zn and V). Results revealed that mean pH, wet and dry density and moisture content of the waste are 6.31, 1532 kg/m3, 1879 kg/m3and 15.35 % respectively. Magnetite, SiO2, P2O5, CaO, Al2O3and MgO were the main constituents of the waste with the weigh percent order of 68.88, 5.91, 3.39, 2.64, 2.59 and 1.76% respectively. Toxicity Characteristic Leaching Procedure (TCLP) test results for some heavy metals showed that mean elemental concentrations of Cd, Co, Cr, Mn, Ni, Pb, V and Zn in leachate were 0.06, 1.55, 5.49, 36.32, 209.10, 0.58, 314.06 and 24.84 mg/lit respectively. According to specific wastes act of Iran this waste can be classified as hazardous due to presence of heavy metals and leaching characteristics and should be disposed regarding hazardous waste disposal considerations.
 ENVIRONMENTAL GEOCHEMISTRY OF HEAVY METALS IN A SEDIMENT CORE OFF BUSHEHR, PERSIAN GULF
作者  A.R. Karbassi, Gh.R. Nabi-Bidhendi and I. Bayati
作者单位  
期刊  Iranian Journal of Environmental Health Science and Engineering 卷期  Vol. 2, No. 4, 2005 时间  2009.12.25
关键词  Persian Gulf , geochemistry, sediment, core, metal, pollution, oil
摘要   In present study, the geochemistry of a sediment core from the Persian Gulf is investigated. The sources of trace elements (Cu, Zn, Pb, Ni, Cr ,Mn) have been investigated by the method of cluster analysis as well as chemical partitioning techniques. Cluster analysis shows that Pb, Cu, Cr and Zn are originated from oil pollution sources taking into account Zn as an oil pollution indicator. Higher concentrations of Mn at depth of 7cm clearly shows the movement of Mn from the lower layer of the sediment core. Considerable amount of Mn, Pb and Cu are found in lithogenous portion The results of partition studies has revealed the percentile of anthropogenic portion of metals as:Mn (46%)> pb (40%)> Cu (18%)> Zn (12.8%)> Fe (2.4%)> Cr & Ni (0.03). Finally, the concentration of studied metals are compared with those of mean crust and mean world sediments. Though concentrations of a few metals are higher than mean crust and men world sediments but Cr inspite of its higher concentration is mainly derived from natural resources.
 SITE SELECTION OF MUNICIPAL SOLID WASTE LANDFILLS USING ANALYTICAL HIERARCHY PROCESS METHOD IN A GEO
作者  Javaheri, H;Nasrabadi, T.;Jafarian, M. H.;Rowshan, G. R. & Khoshnam, H.
作者单位  
期刊  Iranian Journal of Environmental Health Science and Engineering 卷期  Vol. 3, No. 3, 2006 时间  2009.12.05
关键词  Analytical hierarchy process, geographical information technology, landfill, site selection
摘要   Municipal solid waste generation is among the most significant sources which threaten the global environmental health. As an ideal selection depends on considering several independent factors concerning land use, socio economy and hydrogeology, the use of a multi criteria evaluation method seems inevitable. Taking benefit of geographic information system as a tool in combination with geographical information technology, equips the spatial decision support systems in appropriate site selection of sanitary landfills. The present study involves a kind of multi criteria evaluation method under the name of weighted linear combination by using geographical information technology as a practical instrument to evaluate the suitability of the vicinity of Giroft city in Kerman province of Iran for landfill. Water permeability, slope, distance from rivers, depth of underground watertable, distance from residential areas, distance from generation centers, general environmental criterion and distance from roads are the criteria which have been taken in to consideration in the process of analyzing. Superposing all of the raster type layers including geomorphologic, hydrologic, humanistic and land use criteria in land suitability, the final zoning of appropriate, fairly appropriate and inappropriate districts have been identified. Considering relative priority of all criteria in comparison with others, a specific weight is designated to each criterion according to their total influence on the whole process of decision making. The results from the application of the presented methodology are zones for landfill with varying zonal land suitability. Finally the zones will be ranked in descending order to indicate the priority of different options in front of the eyes of decision makers. The results achieved by this study may help policy makers of Giroft city by a variety of options for being considered as sanitary landfill locations.
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