اوﻟﻮﯾﺖ ﺑﻨﺪي ﻣﯿﺰان آﻟﻮدﮔﯽ ﻓﻠﺰات ﺑﺎ اﺳﺘﻔﺎده ازﺷﺎﺧﺺ ﻫﺎي ﺑﺎر آﻟﻮدﮔﯽ و ﭘﺘﺎﻧﺴﯿﻞ ﺧﻄﺮات ﺑﯿﻮﻟﻮژﯾﮏ در رﺳﻮﺑﺎت ﺳﻄﺤﯽ رودﺧﺎﻧﻪﻫﺎي ﺳﻮاﺣﻞ ﺟﻨﻮب ﺷﺮﻗﯽ درﯾﺎي ﺧﺰر

Prioritizing the Amount of Contamination of Metals Using Pollution Load Factors and Potential Biologic Hazards in the Surface Sediments of the Rivers of the Southeast Coast of the Caspian Sea

زﻣﯿﻨﻪ و ﻫﺪف: رﺳﻮﺑﺎت ﺑﻪﻋﻨﻮان ﻣﻬﻢﺗﺮﯾﻦ ﻣﺤﻞ ذﺧﯿﺮه و ﺟﺬب ﻓﻠﺰات و آﻻﯾﻨﺪهﻫﺎي دﯾﮕﺮ در اﮐﻮﺳﯿﺴﺘﻢﻫﺎي آﺑﯽ ﻣﺤﺴﻮب ﻣﯽﺷﻮﻧﺪ و ﻣﯽ ﺗﻮاﻧﻨﺪ ﮐﯿﻔﯿﺖ ﺳﯿﺴﺘﻢﻫﺎي آﺑﯽ را ﻣﻨﻌﮑﺲ ﮐﻨﻨﺪ. در اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﻣﯿﺰان آﻟﻮدﮔﯽ رﺳﻮﺑﺎت ﺑﻪ ﻓﻠﺰات روي، ﻣﺲ، ﺳﺮب و ﮐﺎدﻣﯿﻮم ﺑﺮاﺳﺎس ﺷﺎﺧﺺ ﺑﺎر آﻟﻮدﮔﯽ )PLI( و ارزﯾﺎﺑﯽ ﻣﯿﺰان ﺧﻄﺮات ﻋﻨﺎﺻﺮ ﻓﻠﺰي ﺑﺮ روي ﻣﻮﺟﻮدات زﻧﺪه ﺑﺮاﺳﺎس ﺷﺎﺧﺺ اوﻟﻮﯾﺖﺑﻨﺪي ﭘﺘﺎﻧﺴﯿﻞ ﺧﻄﺮات ﺑﯿﻮﻟﻮژﯾﮏ )MERMQ( در رﺳﻮﺑﺎت ﺳﻄﺤﯽ رودﺧﺎﻧﻪﻫﺎي ﺳﻮاﺣﻞ ﺟﻨﻮﺑﯽ ﺷﺮﻗﯽ درﯾﺎي ﺧﺰر اﻧﺠﺎم ﺷﺪ. روش ﺑﺮرﺳﯽ: ﺑﻪ ﻣﻨﻈﻮر ﺳﻨﺠﺶ و ﺗﻌﯿﯿﻦ ﺷﺎﺧﺺﻫﺎي آﻟﻮدﮔﯽ ﻓﻠﺰات، ﻧﻤﻮﻧﻪﺑﺮداري از رﺳﻮﺑﺎت ﺳﻄﺤﯽ ﻣﺼﺐ و ﻓﺎﺻﻠﻪ 1000ﻣﺘﺮ از ﻣﺼﺐ ﺑﺮﺧﯽ رودﺧﺎﻧﻪﻫﺎي ﺳﻮاﺣﻞ ﺟﻨﻮب ﺷﺮﻗﯽ درﯾﺎي ﺧﺰر ﺷﺎﻣﻞ ﮔﺮﮔﺎنرود، ﻗﺮهﺳﻮ، ﻧﮑﺎءرود، ﺗﺠﻦ، ﺗﺎﻻر و ﺑﺎﺑﻠﺮود اﻧﺠﺎم ﭘﺬﯾﺮﻓﺖ. ﻧﻤﻮﻧﻪﻫﺎ در آزﻣﺎﯾﺸﮕﺎه ﺑﺎ اﺳﺘﻔﺎده از ﻣﺨﻠﻮط ﺳﻪ اﺳﯿﺪ ﻧﯿﺘﺮﯾﮏ، ﻓﻠﻮرﯾﺪرﯾﮏ و ﮐﻠﺮﯾﺪرﯾﮏ آﻣﺎدهﺳﺎزي ﮔﺮدﯾﺪ و ﺳﭙﺲ ﺑﻪ وﺳﯿﻠﻪ دﺳﺘﮕﺎه ﺟﺬب اﺗﻤﯽ ﻣﻮرد آﻧﺎﻟﯿﺰ ﻗﺮار ﮔﺮﻓﺘﻨﺪ. ﯾﺎﻓﺘﻪﻫﺎ: ﻧﺘﺎﯾﺞ ﺗﺤﻘﯿﻖ ﺣﺎﺿﺮ، ﮔﻮﯾﺎي آن اﺳﺖ ﮐﻪ ﻣﯿﺰان ﺷﺎﺧﺺ MERMQ ﻋﻨﺎﺻﺮ ﻓﻠﺰي در رﺳﻮﺑﺎت رودﺧﺎﻧﻪﻫﺎي ﺳﻮاﺣﻞ ﺟﻨﻮﺑﯽ درﯾﺎي ﺧﺰر ﺑﯿﻦ 0/073 ﺗﺎ 0/12 و ﻣﯿﺰان ﺷﺎﺧﺺ آﻟﻮدﮔﯽ PLI ﺑﯿﻦ 0/36 ﺗﺎ 0/58 ﻣﺘﻐﯿﺮ ﺑﻮده اﺳﺖ. ﻧﺘﺎﯾﺞ ﻣﻘﺎﯾﺴﻪ ﻏﻠﻈﺖ ﻓﻠﺰات در ﻧﻤﻮﻧﻪﻫﺎي رﺳﻮب ﺳﻄﺤﯽ ﺑﺎ اﺳﺘﺎﻧﺪارد ﮐﯿﻔﯿﺖ رﺳﻮب )NOAA( ﻧﺸﺎن داد ﮐﻪ در ﺗﻤﺎم اﯾﺴﺘﮕﺎهﻫﺎي ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﻣﻘﺪار ﻋﻨﺎﺻﺮ اﻧﺪازهﮔﯿﺮي ﺷﺪه ﮐﻢﺗﺮ از ﻣﻘﺪار ERL ﻣﯽﺑﺎﺷﺪ. ﻧﺘﯿﺠﻪﮔﯿﺮي: ﻧﺘﺎﯾﺞ ﺷﺎﺧﺺ اوﻟﻮﯾﺖﺑﻨﺪي ﭘﺘﺎﻧﺴﯿﻞ ﺧﻄﺮات ﺑﯿﻮﻟﻮژﯾﮏ )MERMQ( ﺑﺮاي رﺳﻮﺑﺎت ﻧﺸﺎن داد ﮐﻪ در ﻣﺼﺐ رودﺧﺎﻧﻪﻫﺎي ﻗﺮهﺳﻮ، ﺗﺎﻻر و ﻓﺎﺻﻠﻪ 1000ﻣﺘﺮ از ﻣﺼﺐ رودﺧﺎﻧﻪ ﺑﺎﺑﻠﺮود از ﻟﺤﺎظ اوﻟﻮﯾﺖﺑﻨﺪي ﻣﯿﺰان ﺧﻄﺮات ﺑﯿﻮﻟﻮژﯾﮏ در ﺳﻄﺢ اوﻟﻮﯾﺖ ﭘﺎﯾﯿﻦ ﺗﺎ ﻣﺘﻮﺳﻂ ﻗﺮار دارد و در دﯾﮕﺮ اﯾﺴﺘﮕﺎهﻫﺎي ﻣﻮرد ﻣﻄﺎﻟﻌﻪ در اوﻟﻮﯾﺖ ﭘﺎﯾﯿﻦ ﻗﺮار ﮔﺮﻓﺘﻪاﻧﺪ. ﻧﺘﺎﯾﺞ ﺷﺎﺧﺺ آﻟﻮدﮔﯽ PLI ﻧﺸﺎن داد ﮐﻪ ﻣﯿﺰان آﻟﻮدﮔﯽ رﺳﻮﺑﺎت ﺑﻪ ﻓﻠﺰات در ﺳﻄﺢ آﻟﻮدﮔﯽ ﮐﻢ ﻣﯽﺑﺎﺷﺪ. ﻧﻬﺎﯾﺘﺎً ﻣﯽﺗﻮان اﺷﺎره ﻧﻤﻮد ﮐﻪ اﻋﻤﺎل رﻫﻨﻤﻮدﻫﺎي ﻣﺪﯾﺮﯾﺘﯽ ﺻﺤﯿﺢ از ﻗﺒﯿﻞ، دﻓﻊ اﺻﻮﻟﯽ ﻓﺎﺿﻼبﻫﺎي ﺷﻬﺮي، روﺳﺘﺎﯾﯽ و ﺻﻨﻌﺘﯽ، اﺳﺘﻔﺎده از آﻓﺖﮐﺶﻫﺎي ﻣﻨﺎﺳﺐ و ﻫﻤﭽﻨﯿﻦ ﻣﻄﺎﻟﻌﺎت ﻫﻢزﻣﺎن ﻏﻠﻈﺖ ﻋﻨﺎﺻﺮ در آب، رﺳﻮب و ﺟﺎﻧﺪاران در رودﺧﺎﻧﻪﻫﺎ ﺑﻪ ﺻﻮرت دورهاي ﻣﯽﺗﻮاﻧﺪ در ﺑﻬﺒﻮد وﺿﻌﯿﺖ ﻓﻌﻠﯽ ﻣﻨﻄﻘﻪ ﻣﻮﺛﺮ ﺑﺎﺷﺪ.

Sediments are the most important storage and uptake of metals and other pollutants in aquatic ecosystems and can reflect the quality of aquatic systems. In this study, sediment contamination to zinc, copper, lead and cadmium metals based on pollution index (PLI) and evaluation of metal element hazards on living organisms based on biological hazard potential index (MERMQ) in surface sediments of rivers in the southeast coast of the Caspian Sea was performed. Methods: In order to measure and determine the indicators of metal pollution, sampling of surface sediments of the estuary and a distance of 1000 meters from the estuary of some rivers on the southeastern shores of the Caspian Sea including Gorganrood, Qarahsu, Nekaroudeh, Tajna, Talar and Babolrood was performed. Samples were prepared in the laboratory using a mixture of three nitric acids, fluoride and hydrochloric acid and then analyzed by atomic absorption spectrometry. Results: The results of the present study indicate that the MERMQ index of metallic elements in the sediments of rivers on the southern shores of the Caspian Sea ranged from 0.073 to 0.12 and the PLI pollution index ranged from 0.36 to 0.58. The results of comparing the concentration of metals in surface sediment samples with the sediment quality standard (NOAA) showed that in all studied stations the amount of measured elements is less than the amount of ERL. Conclusion: Results of MERMQ for sediments demonstrated that in estuaries of Gharesou and Talar river and 1000 metres from Babolroud, the prioritization of biological hazards is in low to medium level and in other stations in the study is in low level. Besides, the results of PLI in sediments Indicated that level of sediments’ pollution to heavy metals is in low level.