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چکیده
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Soil, air and water, are three important components of the environment. Organic pollutants and heavy metals are one of the environmental problems and crises around the world. Heavy metal accumulation in environment is one of major problems caused by inorganic contaminants. Nowadays environment pollution is getting considerable public attention since the magnitude of this problem is growing rapidly. Heavy metals are the most dangerous substances in the environment due to their high level of durability and toxicity to the biota. Dhi Qar is a Governorate located in the southern part of Iraq with main economic activities such as agriculture, engineering and textile industries, oil and gas production, cattle breading, and fishing. Contamination of agricultural soils with toxic heavy metals has been an environmental problem in Dhi-Qar. This research was conducted to investigate densities of heavy metals (Lead, Cadmium, Copper, Zinc and Manganese) in soil and samples of three plants (Alhagi maurorum, Suaeda vermiculata and Tamarix africana) gathered from three sites (near a farm, near refinery and near thermal power plant) in three periods (summer, autumn and winter). Results showed that highest amount of Pb recorded in soils of near refinery and power plant (310.8 and 293.66 µg/g, respectively). The highest Cd and Zn concentrations measured in the soil of near refinery (11 and 38.18 µg/g respectively). The results showed that the highest Cu were recorded in the soils of near refinery and power plant (44.63 and 44 µg/g, respectively). The maximum amount of Pb and Cd in soil was measured in winter, and for Cu and Zn in autumn. S. vermiculata showed the highest rate of Pb and Cd accumulation. Whereas A. maurorum accumulated the highest rate of Zn, Cu and Mn. The results of this study also revealed that in plants overall, the highest amount of Pb, Zn and Mn were measured in winter (0.0646, 0.3165 and 0.3164 mg/l, respectively), and for Cd and Cu in autumn (0.0015 and 0.1673 mg/l respectively). Also, the results showed that the highest amount of heavy metals were measured as Pb in T. africana near refinery, Cd, Zn, Mn and Cu in A. maurorum in power plant. Hence these plants can be used in an environment-friendly approach for treating heavy metal contaminated soils near polluted environmental especially industrial areas.
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