Heavy metal contamination of soils is a widespread problem in Zanjan province located in North West Iran due to natural pedo geochemical background and anthropogenic sources. The province is highly polluted by some he...Heavy metal contamination of soils is a widespread problem in Zanjan province located in North West Iran due to natural pedo geochemical background and anthropogenic sources. The province is highly polluted by some heavy metals due to the presence of mineral resources notably Lead and Zinc, their improper utilization, and also the development of a number of related industries. Bonab district was selected for detail study and the objectives of the study were set to evaluate the total as well as bioavailable fraction of heavy metals in surficial soils within the studied area. 72 soil samples were collected and analyzed for heavy metal contamination by Atomic Absorption Spectrometry (AAS). The obtained results when compared with WHO and USEPA standards show a very high concentration of some toxic metals. Soils were basically polluted by Pb, Zn, Cu, and Cd. Bioavailable fraction of studied metals were also measured with formation of metal complex with Diethylene tri amine penta acetic acid (DTPA) agent. To find the share of the anthropogenic sources in the contamination of soils, the Enrichment factor (EF) and Geological Accumulation Index were measured and the distribution maps were drawn using Arc GIS (9.3). Highest concentrations of some toxic metals were found as isolated patches around the Bonab Industrial Town as well as within and around the most populated areas of the district notably Zanjan city indicating its anthropogenic origin.展开更多
The salt domes of the west Zanjan (Central Iran) are the most important structures in the study area. They have been formed by the uplifting and erosion together under low humidity and dry and warm climate condition. ...The salt domes of the west Zanjan (Central Iran) are the most important structures in the study area. They have been formed by the uplifting and erosion together under low humidity and dry and warm climate condition. The salt rocks with near to 200 meters thickness are related to lower member of the Upper Red Formation (Early Miocene) that deposited in the inverted back arc basin. They have been formed in the Central Iran basin after the Arabian-Eurasian convergence. Based on filed works and preparation of geologic map, salt domes have been cropped out during regional uplifting and erosion along hinge zone of a longitudinal anticline. Also, there is no evidence for salt diapirism and so, they are different from some salt diapirs in the southwestern margin of Zanjan that is investigated by other researchers.展开更多
文摘Heavy metal contamination of soils is a widespread problem in Zanjan province located in North West Iran due to natural pedo geochemical background and anthropogenic sources. The province is highly polluted by some heavy metals due to the presence of mineral resources notably Lead and Zinc, their improper utilization, and also the development of a number of related industries. Bonab district was selected for detail study and the objectives of the study were set to evaluate the total as well as bioavailable fraction of heavy metals in surficial soils within the studied area. 72 soil samples were collected and analyzed for heavy metal contamination by Atomic Absorption Spectrometry (AAS). The obtained results when compared with WHO and USEPA standards show a very high concentration of some toxic metals. Soils were basically polluted by Pb, Zn, Cu, and Cd. Bioavailable fraction of studied metals were also measured with formation of metal complex with Diethylene tri amine penta acetic acid (DTPA) agent. To find the share of the anthropogenic sources in the contamination of soils, the Enrichment factor (EF) and Geological Accumulation Index were measured and the distribution maps were drawn using Arc GIS (9.3). Highest concentrations of some toxic metals were found as isolated patches around the Bonab Industrial Town as well as within and around the most populated areas of the district notably Zanjan city indicating its anthropogenic origin.
文摘The salt domes of the west Zanjan (Central Iran) are the most important structures in the study area. They have been formed by the uplifting and erosion together under low humidity and dry and warm climate condition. The salt rocks with near to 200 meters thickness are related to lower member of the Upper Red Formation (Early Miocene) that deposited in the inverted back arc basin. They have been formed in the Central Iran basin after the Arabian-Eurasian convergence. Based on filed works and preparation of geologic map, salt domes have been cropped out during regional uplifting and erosion along hinge zone of a longitudinal anticline. Also, there is no evidence for salt diapirism and so, they are different from some salt diapirs in the southwestern margin of Zanjan that is investigated by other researchers.
