Mohammad Ebrahim Fazel Valipour
Abstract
AbstractBackground and Aim: Heavy metals contamination of soils is one of the main environmental problems. Heavy metals are considered as one most dangerous groups of pollutants because of their toxicity and stability. The biological and ecological importance of heavy metals is due to their characteristics ...
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AbstractBackground and Aim: Heavy metals contamination of soils is one of the main environmental problems. Heavy metals are considered as one most dangerous groups of pollutants because of their toxicity and stability. The biological and ecological importance of heavy metals is due to their characteristics of polluting, their toxicity, persistence and bioaccumulation. The aim of this study was to investigate the spatial distribution of heavy metals in region Dehnow Shandiz (North West of mashhad).Materials and Methods: In the present study, 20 soil samples (10-30 cm depth) collected and total concentration of As, Cd, Co, Cr and Ni were measured using Atomic absorption spectrophotometer device. Also, some other soil properties including PH, Organic carbon, CEC and soil texture proportions were measured.Results: The results showed that the average concentrations of As, Cd, Co, Cr and Ni in the study area were 10.87, 0.26, 14.8, 56.6 and 68.2 mg/kg respectively. Also the results of statistical analysis showed that the standard deviations of As, Cd, Co, Cr and Ni in the study area were 1.97, 0.16, 1.32, 19.47 and 17.39 respectively.Conclusion: The results indicate that the average concentration of Ni in the soil of study area were higher than the standard of the Environmental Protection Organization of Iran and As, Cd, Co and Cr were lower than the standard. The presence of serpentinite soils has increased the concentration of nickel in the region.Document Type: Research article
Abbas Ali Zamani; Elham Ahmadpour; Abdolhosein Zanganeh; Younes Khosravi
Abstract
Background & objective: Cement manufacturing is the most important and influential industry in the economic prosperity of the country. However, this can be an entrance source for heavy metals to environment. The main objectives of the present study were to identify the spatial variability and main ...
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Background & objective: Cement manufacturing is the most important and influential industry in the economic prosperity of the country. However, this can be an entrance source for heavy metals to environment. The main objectives of the present study were to identify the spatial variability and main sources of heavy metals including Cr, Mn, Ni, Co, Cu, Cd, As and Zn in surface soils of the closed Kurdistan cement factory zone by conducting multivariate geostatistical analysis assisted with ArcGIS 10.2 tool. Multivariate geostatistics was used to survey the spatial distribution of studied heavy metals and their reasons in the studied area. Materials & Methods: In the present study, 88 samples of surface soils were collected in radiuses of 500, 1000, 2000 and 3000 m from the center of the cement factory from two depths of 0–15 and 15-30 cm. Results: According to the gained results, three principal factors were appeared with more than 90% of the total variance through multivariate statistical analysis for heavy metals. For mapping the distribution of the heavy metals amounts, four different models including circular, spherical, exponential and Gaussian with methods of simple Kriging, ordinary Kriging, universal and simple Co-Kriging were identified as the optimum models using ArcGIS 10.2.. The accoracy of the methods were evaluated using coefficient determination, mean absolute error, mean bias error and root mean square error. Conclusion: Heavy metals mapping confirmed that the levels of Cd, As, Pb and Cu in surface soils closed to the factory are higher than global average amount. Also, it can be mentioned that geological structure of the area plays most important role in soil pollution. However, anthropogenic activities, particularly cement plant are considered as another effective factor on soil pollution in the studied area.