بررسي آلودگي آب زيرزميني محدوده پالايشگاه شازند به BTEX و MTBE

The study of oil-contamination groundwater due to Shazand Refinery

زﻣﯿﻨﻪ و ﻫﺪف: ﭘﺎﻻﯾﺸﮕﺎه ﺷﺎزﻧﺪ ﺑﻪ ﻋﻨﻮان ﺑﺰرگﺗﺮﯾﻦ واﺣﺪ ﺗﻮﻟﯿﺪ ﺑﻨﺰﯾﻦ در ﺧﺎورﻣﯿﺎﻧﻪ در ﻓﺎﺻﻠﻪ 22 ﮐﯿﻠﻮﻣﺘﺮي ﺟﻨﻮب ﻏﺮﺑﯽ اراك و در ﺷﻤﺎل ﺷﺮﻗﯽ دﺷﺖ ﺷﺎزﻧﺪ ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ. ﺑﻪ دﻟﯿﻞ وﺟﻮد ﺗﺄﺳﯿﺴﺎت ﭘﺎﻻﯾﺸﯽ، ﻣﺨﺎزن ﻣﺘﻌﺪد ﻧﮕﻬﺪاري ﻧﻔﺖ ﺧﺎم و ﻓﺮآوردهﻫﺎي ﻧﻔﺘﯽ، ﺧﻄﻮط ﻟﻮﻟﻪ اﻧﺘﻘﺎل ﻓﺮاودهﻫﺎي ﻧﻔﺘﯽ ﻣﺮﺑﻮط ﺑﻪ ﭘﺎﻻﯾﺸﮕﺎه ﺷﺎزﻧﺪ، اﺣﺘﻤﺎل ﻧﺸﺖ ﻣﻮاد آﻻﯾﻨﺪه از ﻣﺨﺎزن و ﻟﻮﻟﻪﻫﺎ ﺑـﻪ ﻣﺤـ ﯿﻂ ﺧـﺎك و آب زﯾﺮزﻣﯿﻨـﯽ وﺟـﻮد دارد. آﺑﺨﻮان دﺷﺖ ﺷﺎزﻧﺪ از ﻧﻮع آزاد و ﻣﺘﺸﮑﻞ از رﺳﻮﺑﺎت آﺑﺮﻓﺘﯽ داﻧـﻪ درﺷـﺖ ﺑـﻮده و ﺟﻬـﺖ ﺟﺮﯾـﺎن از ﭘﺎﻻﯾﺸـﮕﺎه ﺑـﻪ ﺳـﻤﺖ ﭼـﺎه ﻫـﺎي ﮐﺸﺎورزي، ﻣﺮﮐﺰ دﺷﺖ ﻣﯽﺑﺎﺷﺪ. ﺑﻨﺎﺑﺮاﯾﻦ، آﻟﻮدﮔﯽ آب زﯾﺮزﻣﯿﻨﯽ ﻧﺎﺷﯽ از آﻻﯾﻨﺪهﻫﺎي ﻧﻔﺘﯽ ﭘﺎﻻﯾﺸﮕﺎه ﺷﺎزﻧﺪ ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺖ. روش ﺑﺮرﺳﯽ: در اﯾﻦ ﭘﮋوﻫﺶ، از 16 ﺣﻠﻘﻪ ﭼﺎه در ﻣﻨﻄﻘﻪ ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﻧﻤﻮﻧﻪﺑﺮداري در ﺧﺮداد ﻣﺎه 1394 ﺻﻮرت ﮔﺮﻓﺖ و ﺟﻬـﺖ ﺗﺠﺰﯾـﻪ و ﺗﺤﻠﯿﻞ ﺑﻪ آزﻣﺎﯾﺸﮕﺎه ارﺳﺎل ﮔﺮدﯾﺪ. آزﻣﺎﯾﺶ ﺗﺮﮐﯿﺒﺎت BTEX و MTBE ﺑﺮاﺳﺎس روش ﮔﺎزﮐﺮوﻣﺎﺗﻮﮔﺮاﻓﯽ ﺑﺎ آﺷﮑﺎرﺳﺎز ﯾﻮﻧﯿﺰاﺳﯿﻮن ﺷﻌﻠﻪاي )GC-FID( 4 اﻧﺠﺎم ﺷﺪ. ﺟﻬﺖ ﺑﺮرﺳﯽ آﻟﻮدﮔﯽ ﻣﻨﻄﻘﻪ ﻣﻮرد ﻣﻄﺎﻟﻌﻪ، ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از آﻧﺎﻟﯿﺰ ﺗﺮﮐﯿﺒﺎت BTEX و MTBE ﺑﺎ اﺳـﺘﺎﻧﺪاردﻫﺎي ﻣﻌﺘﺒﺮ آب ﺷﺮب و ﮐﺸﺎورزي ﻣﻘﺎﯾﺴﻪ ﮔﺮدﯾﺪ. ﯾﺎﻓﺘﻪﻫﺎ: ﻧﺘﺎﯾﺞ ﻧﺸﺎندﻫﻨﺪه آﻟﻮده ﺑﻮدن 6 ﺣﻠﻘﻪ ﭼﺎه واﻗﻊ در ﻗﺴﻤﺖ ﺷﺮق و ﺟﻨﻮب ﭘﺎﻻﯾﺸﮕﺎه و ﺷﺮق و ﺷﻤﺎل ﺷﺮﻗﯽ ﭘﺘﺮوﺷﯿﻤﯽ ﻧﺴـﺒﺖ ﺑـﻪ ﺗﺮﮐﯿﺒﺎت BTEX و MTBE اﺳﺖ. ﺑﺨﺸﯽ از آﻟﻮدﮔﯽﻫﺎي ﻣﻮﺟﻮد در آب زﯾﺮزﻣﯿﻨﯽ ﻣﻨﺸﺄ ﺟﻮي داﺷﺘﻪ و از ﻃﺮﯾـﻖ ﻧـﺰوﻻت ﺟـﻮي وارد آب زﯾﺮزﻣﯿﻨﯽ ﻣﻨﻄﻘﻪ ﺷﺪه اﺳﺖ و ﺑﺨﺶ دﯾﮕﺮ ﻣﺮﺑﻮط ﺑﻪ ﻧﺸﺖ از ﺗﺄﺳﯿﺴﺎت، ﻣﺨﺎزن و ﺧﻄﻮط اﻧﺘﻘﺎل ﻣﯽﺑﺎﺷﺪ. ﺑﺤﺚ و ﻧﺘﯿﺠﻪﮔﯿﺮي: ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ آﻟﻮدﮔﯽ ﻣﻮﺟﻮد در ﻣﻨﻄﻘﻪ و آﻟﻮدﮔﯽﻫﺎي اﺣﺘﻤﺎﻟﯽ دﯾﮕﺮ، ﭘﯿﺸﻨﻬﺎد ﻣﯽﺷﻮد ﭘﯿﺶ از ﻫﺮ اﻗﺪام ﺑﺮاي ﭘﺎكﺳﺎزي، ﻣﻨﺸﺄ دﻗﯿﻖ آﻟﻮدﮔﯽ ﺷﻨﺎﺳﺎﯾﯽ و ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﺷﺮاﯾﻂ ﻣﻨﻄﻘﻪ و ﻧﻈﺮات ﮐﺎرﺷﻨﺎﺳﯽ روش ﻣﻨﺎﺳﺐ ﺟﻬﺖ ﭘﺎكﺳﺎزي ﻣﻨﻄﻘﻪ اﻧﺘﺨﺎب ﮔﺮدد.

Background and Purpose: Shazand oil refinery, as the biggest producer of gasoline in the Middle East, is located 22 km to the Southwest of Arak and the Northeast of Shazand plain. Due to presence of various storage tanks of crude oil and oil products, processing unites and conveyance lines of oil products, it is very possible the leakage of pollution from tanks and conveyance lines into the soil and groundwater. Shazand plain aquifer is an unconfined and consists of coarse-grained alluvial deposits with a flow direction from the refinery to the agriculture wells which are located at the center of plain. Hence, groundwater contamination, which was resulted from the oil pollution of Shazand refinery was investigated. Material and Method: In this study, 16 wells were sampled in study area on Jun 2015 and they delivered to laboratory for analyzing. Compound BTEX and MTBE analyzed by gas chromatography with flame ionization detector (GC-FID4). To investigate contamination in study area, results of analyses of BTEX and MTBE were compared with valid standards of drinking and agriculture water. Result: The results show that 6 wells are polluted at the East and South of refinery and the east and Northeast of petrochemical complex. A part of the groundwater contamination was due to atmospheric washout and the other part relates to leak from utilities, tanks and conveyance lines. Discussion & Conclusion: Considering the already existing and the other possible forms of contamination in the area, it is proposed that before taking, the exact source of contamination be identified and proper measures to clean the area be chosen based on expert opinion.