تعيين سهم منبع طبيعي و انسان ساخت عناصر فلزي مس، روي، سرب و كادميم در رسوبات سطحي سواحل ايراني درياي خزر با استفاده از استخراج پي‌درپي

Determination natural and anthropogenic sources of Cu, Zn, Pb, Cd in the Iranian Coast of Caspian Sea surface sediments using sequential extraction Technique

رﺳﻮﺑﺎت ﺳﺎﺣﻠﯽ ﺑﻪ ﻋﻨﻮان ﻧﺸﺎﻧﮕﺮﻫﺎي ﺣﺴﺎس ﺟﻬﺖ ﭘﺎﯾﺶ آﻟﻮدﮔﯽ در ﻣﻨﺎﻃﻖ ﺳﺎﺣﻠﯽ ﺑﻪ ﮐﺎر ﻣﯽروﻧﺪ. ﻋﻨﺎﺻﺮ ﻓﻠﺰي در رﺳﻮﺑﺎت ﺳﻄﺤﯽ از ﻣﻨﺎﺑﻊ ﻃﺒﯿﻌﯽ و اﻧﺴﺎن ﺳﺎﺧﺖ ﺳﺮﭼﺸﻤﻪ ﻣﯽﮔﯿﺮﻧﺪ، ﺑﻨﺎﺑﺮاﯾﻦ در اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﻪ ﻣﻨﻈﻮر ﺗﻌﯿﯿﻦ ﺳﻬﻢ ﻣﻨﺎﺑﻊ ﻃﺒﯿﻌﯽ و اﻧﺴﺎن ﺳﺎﺧﺖ ﻓﻠﺰات ﻣﺲ، روي، ﺳﺮب و ﮐﺎدﻣﯿﻢ رﺳﻮﺑﺎت ﺳﻄﺤﯽ درﯾﺎي ﺧﺰر، ﻧﻤﻮﻧﻪﺑﺮداري ﻓﺼﻠﯽ در ﺳﺎل 1392 اﻧﺠﺎم ﺷﺪ. ﺗﻌﺪاد 72 )ﺑﺎ ﺳﻪ ﺗﮑﺮار( ﻧﻤﻮﻧﻪ رﺳﻮب از ﻧﯿﻢ ﺧﻂﻫﺎي ﺗﻨﮑﺎﺑﻦ و ﺑﻨﺪر اﻣﯿﺮآﺑﺎد در اﻋﻤﺎق 10 ،5 و 20 ﻣﺘﺮي ﺑﻮﺳﯿﻠﮥ ﻧﻤﻮﻧﻪﺑﺮدار ﮔﺮب ون وﯾﻦ ﺟﻤﻊآوري ﮔﺮدﯾﺪ. ﻧﻤﻮﻧﻪﻫﺎ ﺑﺎ روش اﺳﺘﺨﺮاج ﭘﯽدرﭘﯽ ﻏﻠﻈﺖ ﮐﻞ ﻓﻠﺰات، ﺑﺨﺶﻫﺎي ﻧﺎﭘﺎﯾﺪار و ﭘﺎﯾﺪار ﻧﻤﻮﻧﻪﻫﺎ ﻫﻀﻢ ﮔﺮدﯾﺪﻧﺪ و ﺳﭙﺲ ﻏﻠﻈﺖ ﻓﻠﺰات ﺑﻮﺳﯿﻠﮥ دﺳﺘﮕﺎه ﺟﺬب اﺗﻤﯽ اﻧﺪازهﮔﯿﺮي ﮔﺮدﯾﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﺣﺪاﮐﺜﺮ و ﺣﺪاﻗﻞ ﻏﻠﻈﺖ ﻣﺲ، روي، ﺳﺮب و ﮐﺎدﻣﯿﻢ در ﺑﺨﺶ ﻧﺎﭘﺎﯾﺪار ﺑﻪ ﺗﺮﺗﯿﺐ )19/31- 4/21) ،(0/58- 7/86) ،(0/83- 4/21( و )0/68- 0/31( ﻣﯿﮑﺮوﮔﺮم ﺑﺮ وزن ﻣﺎده ﺧﺸﮏ و در ﺑﺨﺶ ﭘﺎﯾﺪار ) 23/33- 79/19) ،(4/70- 7/14-06/84) ،(4/88( و )0/46- 0/23( ﻣﯿﮑﺮوﮔﺮم ﺑﺮ ﮔﺮم وزن ﻣﺎده ﺧﺸﮏ ﺑﻪ ﺗﺮﺗﯿﺐ ﯾﺎد ﺷﺪه، ﺑﻪ دﺳﺖ آﻣﺪﻧﺪ. ﻧﺘﺎﯾﺞ اﯾﻦ ﺗﺤﻘﯿﻖ ﻫﻤﭽﻨﯿﻦ ﻧﺸﺎن داد ﮐﻪ درﺻﺪ ﺑﺨﺶ ﻧﺎﭘﺎﯾﺪار ﻓﻠﺰ ﮐﺎدﻣﯿﻢ ﺑﺮاﺑﺮ 58/58 درﺻﺪ ﺑﻮده ﮐﻪ ﻧﺸﺎن دﻫﻨﺪة ﺑﯿﺸﺘﺮ ﺑﻮدن ﺳﻬﻢ اﻧﺴﺎﻧﯽ در ﺗﻮزﯾﻊ اﯾﻦ ﻓﻠﺰ ﻣﯽﺑﺎﺷﺪ. در ﺣﺎﻟﯽ ﮐﻪ ﻓﻠﺰات ﻣﺲ )32/%14(، روي )4/%28( و ﺳﺮب )35/%77( داراي ﻣﻨﺸﺎء ﻃﺒﯿﻌﯽ ﺑﻮدﻧﺪ. ﺑﻨﺎﺑﺮاﯾﻦ ﻣﯿﺰان ﻋﻨﺎﺻﺮ ﺳﻤﯽ ﺳﺮب و ﮐﺎدﻣﯿﻢ در ﺑﺨﺶ ﻧﺎﭘﺎﯾﺪار ﮐﻤﺘﺮ از ﺣﺪ اﺳﺘﺎﻧﺪارد ﺑﻮده و ﺑﺮاي ﻣﻮﺟﻮدات ﮐﻒزي ﻣﺸﮑﻠﯽ را اﯾﺠﺎد ﻧﺨﻮاﻫﺪكرد

Coastal sediments as sensitive indicators are employed for monitoring pollution in the coastal areas. Heavy metals in surface sediments originate from natural and/or man-made sources. This study was conducted to determine natural and anthropogenic sources of some heavy metals (Zn, Cu, Cd, Pb) of surface sediment in the southern Caspian Sea during four seasons in 2013-2014. 72 surface sediment samples (with triplicate) were collected at two transects (Tinekabon and Amirabad) and tree depths (5, 10, 20 m) using Van Veen Grab sampler. The heavy metals concentrations of different extraction were measured using atomic absorption spectrometry (AAS) with flame and furnace. Results showed that maximum and minimum concentrations of copper, zinc, lead, and cadmium in the non-resistance part were 0.58-19.31, 0.83-4.21, 4.21-7.86, and 0.31-0.68 and in the resistance part were 4.70-23.33, 4.88-79.19, 7.06-14.84, and 0.23-0.46 µg/g.dw, respectively. In a conclusion, percentage of Cd in the non-resistance part was 58.58% that it contained maximum level among various heavy metals which represents a greater distribution in the anthropogenic origin. While Cu (32.14%), Zn (4.28%) and Pb (35.77%) have natural origin.