7384

6890

كارشناسي ارشد

خاكشناسي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1391

شانزده، 176ص.: مصور، جدول، نقشه، نمودار

ص.ع. به فارسي و انگليسي

حسين خادمي

شمس ا... ايوبي، محمد امير دلاور

21/9/91

نوراله مير غفاري

1396/09/21

كتابنامه

كشاورزي

مهندسي كشاورزي

ID6890

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Factors Affecting the Spatial Distribution of Selected Heavy Metals in Surface Soils of Zanjan and Their Profile Variations Ali Afshari A Afshari66@yahoo com Date of Submission September 05 2012 Department of Soil Science College of Agriculture Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Dr Hossein Khademi E mail hkhademi@cc iut ac ir Abstract Heavy metals are the most important environmental pollutants particularly in areas with highhuman activities The presence of heavy metals in atmosphere soil and water causes problems for all theorganisms The objectives of this research were i to evaluate the spatial variability of the totalconcentration of Pb Zn Cu Cd Cr Co Ni Mn and Fe ii to determine the factors controlling theirdistribution iii to understand the effects of land use on soil magnetic susceptibility and heavy metalsaccumulation and iv to study the profile variability of heavy metals in soils of the Zanjan area An areaof over 2000 km2 in the central part of Zanjan province was selected A total of 241 composite surfacesoil samples 0 10 cm were taken The location of sampling sites was determined using a GPS and theirland use and geology were also recorded Besides a total of 15 soil profiles on dominant parent materialswere excavated and studied After preparation of soil and rock samples they were digested with 5NHNO3 and their heavy metal concentration was measured using an atomic absorption spectrometer Distribution maps of studied parameters were prepared using the kriging technique Besides selectedproperties of the samples including pH EC texture OM carbonates and CEC were determined Themagnetic susceptibility of the soil samples was also measured The spatial distribution of heavy metalsindicated that the concentration of Pb Zn Cu and Cd was highest in soils around Zanjan Soltanieh andindustrial complexes The distribution pattern of all the other heavy metals is mainly controlled by soilparent materials The results also showed that the type of land use affected the total concentration of theelements studied The highest concentration of Pb Zn Cd and Cu was found in urban soils while Cr Coand Ni in soils are mainly controlled by parent materials Fe and Mn have been influenced by bothanthropogenic and lithogenic factors Both cluster analysis and PCA confirmed the results The magneticsusceptibility of soils was highest in urban area further indicating the influence of anthropogenicactivities Frequency dependent magnetic susceptibility was highest in land uses with minimal influenceof human inputs Magnetic susceptibility at both low and high frequency had a positive correlation withPb Zn Cd and sand and a negative correlation with Cr Co Ni silt and clay The analysis of parent rocksshowed that igneous rocks had a high content of Pb Zn Cu Mn and Fe Shales had a high concentrationof Cr Ni Co and Fe Vertical distribution of heavy metals was different among the soil profiles studied In all the pedons the concentration of almost all the elements studied was high in the surface layer Thiscould be attributed to pedogenic processes atmospheric deposition agricultural inputs and thebioextraction process In some profiles the concentration of heavy metals increases with depth whichindicates the influence of parent materials The type of land use also controls the vertical variability ofsome heavy metals Keywords Heavy metals Spatial distribution Kriging Magnetic properties Anthropogenicactivities Parent materials

حسين خادمي

شمس ا... ايوبي، محمد امير دلاور

نوراله مير غفاري