ارزيابي آلودگي خاك هاي اطراف كارخانه آلومينيوم سازي اراك به عناصر آلومينيوم، آهن، منگنز و سرب

Evaluation of Soils Contamination around Aluminum Smelting Plant of Arak City by Aluminum, Iron, Manganese and Lead

زﻣﯿﻨﻪ و ﻫﺪف : ﺑﺎ ﺻﻨﻌﺘﯽ ﺷﺪن ﺷﻬﺮﻫﺎ و اﻓﺰاﯾﺶ ﺗﻌﺪاد ﮐﺎرﺧﺎﻧﺠﺎت، آﻟﻮدﮔﯽ ﺧﺎك رو ﺑﻪ ﮔﺴﺘﺮش ﺑﻮده و ﯾﮑﯽ از ﻣﺸﮑﻼت زﯾﺴﺖ ﻣﺤﯿﻄﯽ ﻗﺮن ﺣﺎﺿﺮ ﺑﻪ ﺣﺴﺎب ﻣﯽآﯾﺪ. ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ اﻫﻤﯿﺖ ﺷﻬﺮ اراك از ﻧﻈﺮ ﻓﻌﺎﻟﯿﺖﻫﺎي ﺻﻨﻌﺘﯽ، ﻫﺪف اﯾﻦ ﭘﮋوﻫﺶ، ﺑﺮرﺳﯽ ﺷﺪت آﻟﻮدﮔﯽ ﺧﺎك ﺑﻪ ﻋﻨﺎﺻﺮ ﻓﻠﺰي در اﻃﺮاف ﮐﺎرﺧﺎﻧﻪ آﻟﻮﻣﯿﻨﯿﻮمﺳﺎزي اﯾﻦ ﺷﻬﺮ ﻣﯽﺑﺎﺷﺪ. روش ﺑﺮرﺳﯽ: ده ﻧﻤﻮﻧﻪ ﻣﺮﮐﺐ ﺧﺎك از ﻋﻤﻖ ﺻﻔﺮ ﺗﺎ 15 ﺳﺎﻧﺘﯽﻣﺘﺮي و در دو ﺟﻬﺖ ﺷﻤﺎل ﺷﺮﻗﯽ و ﺷﻤﺎل ﻏﺮﺑﯽ ﺗﺎ ﺷﻌﺎع 5 ﮐﯿﻠﻮﻣﺘﺮي از ﮐﺎرﺧﺎﻧﻪ ﺑﺮداﺷﺘﻪ ﺷﺪ. ﺟﻬﺖ اﻧﺪازهﮔﯿﺮي ﺷﺪت آﻟﻮدﮔﯽ ﺧﺎك ﺑﻪ ﻋﻨﺎﺻﺮ ﻓﻠﺰي، ﻏﻠﻈﺖﻫﺎي ﮐﻞ ﻋﻨﺎﺻﺮ آﻟﻮﻣﯿﻨﯿﻮم، آﻫﻦ، ﻣﻨﮕﻨﺰ و ﺳﺮب در ﻧﻤﻮﻧﻪﻫﺎي ﺧﺎك ﭘﺲ از ﻋﺼﺎرهﮔﯿﺮي ﺑﺎ اﺳﯿﺪ ﺗﻮﺳﻂ دﺳﺘﮕﺎهICP ﺗﻌﯿﯿﻦ ﮔﺮدﯾﺪﻧﺪ. ﺟﻬﺖ ﺑﺮآورد ﺷﺪت آﻟﻮدﮔﯽ از ﺿﺮﯾﺐ و درﺟﻪ آﻟﻮدﮔﯽ، ﺷﺎﺧﺺ ژﺋﻮاﻧﺒﺎﺷﺖ و ﺿﺮﯾﺐ ﻏﻨﯽﺷﺪﮔﯽ اﺳﺘﻔﺎده ﺷﺪ. ﯾﺎﻓﺘﻪﻫﺎ: ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﺷﺪت آﻟﻮدﮔﯽ ﺧﺎك ﺑﻪ ﻋﻨﺎﺻﺮآﻟﻮﻣﯿﻨﯿﻮم، آﻫﻦ، ﻣﻨﮕﻨﺰ و ﺳﺮب در ﺟﻬﺖ ﺷﻤﺎل ﻏﺮﺑﯽ ﮐﺎرﺧﺎﻧﻪ ﺑﯿﺶﺗﺮ از ﺟﻬﺖ ﺷﻤﺎل ﺷﺮﻗﯽ ﺑﻮده و ﻣﻘﺪار اﯾﻦ ﻋﻨﺎﺻﺮ ﺑﻪ ﺗﺮﺗﯿﺐ ﺑﺮاﺑﺮ ﺑﺎ 567/138 ،23282/1 ،41316/5 و 71/0375 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﮐﯿﻠﻮﮔﺮم ﺧﺎك اﻧﺪازه- ﮔﯿﺮي ﮔﺮدﯾﺪ. ﺑﺤﺚ و ﻧﺘﯿﺠﻪﮔﯿﺮي: ﺑﺮ اﺳﺎس ﺷﺎﺧﺺ ﺿﺮﯾﺐ آﻟﻮدﮔﯽ، ﺷﺪت آﻟﻮدﮔﯽ ﺧﺎكﻫﺎي ﻣﻨﻄﻘﻪ در ﺟﻬﺖ ﺷﻤﺎل ﺷﺮﻗﯽ ﺑﻪ ﻋﻨﺼﺮ آﻟﻮﻣﯿﻨﯿﻮم ﻗﺎﺑﻞ ﺗﻮﺟﻪ و ﺑﻪ ﻋﻨﺎﺻﺮ آﻫﻦ، ﻣﻨﮕﻨﺰ و ﺳﺮب، در ﺣﺪ ﻣﺘﻮﺳﻂ ﺑﻮد ﮐﻪ ﻧﺸﺎن ﻣﯽدﻫﺪ ﮐﻪ ﻓﻌﺎﻟﯿﺖ ﮐﺎرﺧﺎﻧﻪ آﻟﻮﻣﯿﻨﯿﻮمﺳﺎزي اراك ﺑﺎﻋﺚ آﻟﻮدﮔﯽ ﺧﺎك منطقه ﺑﻪ ﻋﻨﺎﺻﺮ ﻓﻠﺰي در ﺣﺪ ﻣﺘﻮﺳﻂ ﺷﺪه اﺳﺖ

Background and Objective: With increase in the number of factories and industrialized cities, soil contamination is becoming an environmental problem in recent century. Considering the industrial activities of Arak city, the aims of this study was to evaluate metal contamination status of soils around Aluminum smelting factory of this city. Method: Ten composite samples were taken from the surface layers (0-15) of soils located in north-west and north-east directions of the factory with a distance interval of 1 km and up to a distance of 5 km from the factory. Total concentration of aluminum, iron, manganese and lead were extracted from the soil samples by acid and determined using ICP device. To determine the pollution intensity of the soils studied, contamination coefficient, degree of contamination, index of geo accumulation and enrichment factor were calculated for the soil samples. Findings: The results showed that the pollution intensities of soils by aluminum, iron, manganese and lead were higher in North West direction compared to North East direction and the total concentration of these elements were 41316.5, 23282.1, 567.13 and 71.04 mg/kg soil respectively. Discussion and Conclusion: According to the contamination coefficients calculated for the soil samples, the pollution intensity of the soils, in the north-west direction, was considerable for aluminum and moderate for iron, manganese and lead and indicated that industrial activities of the factory caused moderately soil pollution by metals.