ﺑﺮرﺳﯽ ﺣﺬف ﺑﯿﻮﻟﻮژﯾﮑﯽ ﮐﺮوم VI ﺑﺎ اﺳﺘﻔﺎده از ﺑﺎﮐﺘﺮي ﻫﺎي ﺟﺪا ﺷﺪه از ﻓﺎﺿﻼب ﺻﻨﻌﺘﯽ ﻣﺠﺘﻤﻊ ﻓﻮﻻد ﻣﺒﺎرﮐﻪ اﺻﻔﻬﺎ ن

Investigation of Biological Removal of Chromium (VI) Using the Isolated Bacteria from Industrial Wastewater of Mobarakeh Steel Complex in Isfahan

زﻣﯿﻨﻪ و ﻫﺪف: ﻓﻠﺰات ﺳــﻨﮕﯿﻦ ﺑﻪ دﻟﯿﻞ ﻣﺎﻫﯿﺖ ﺳــﻤﯽ ﻫﻤﺎﻧﻨﺪ ﺑﺮﺧﯽ ﻣﻮاد آﻟﯽ، در ﻣﺤﯿﻂ ﭘﺎكﺳــﺎزي ﻧﻤﯽﺷــﻮﻧﺪ و دﺳﺘﻪاي از آﻻﯾﻨﺪهﻫﺎي ﭘﺎﯾﺪار و ﻏﯿﺮﻗﺎﺑﻞﺗﺠﺰﯾﻪ ﺑﯿﻮﻟﻮژﯾﮑﯽ را ﺗﺸﮑﯿﻞ ﻣﯽدﻫﻨﺪ. اﯾﻦ ﻋﻨﺎﺻﺮ در ﻧﺘﯿﺠﻪ ﻓﻌﺎﻟﯿﺖﻫﺎي ﻃﺒﯿﻌﯽ ﻣﺎﻧﻨﺪ ﻓﻮران آﺗﺸـﻔﺸـﺎنﻫﺎ و ﻓﻌﺎﻟﯿﺖﻫﺎي اﻧﺴـﺎﻧﯽ ﻣﺜﻞ اﺳـﺘﺨﺮاج ﻣﻌﺎدن، ﺗﻮﻟﯿﺪ ﭘﺴـﺎبﻫﺎي ﺻـﻨﻌﺘﯽ، ﻓﺎﺿـﻼبﻫﺎي ﺷـﻬﺮي و ﺑﺮﺧﯽ از آﻓﺖﮐﺶﻫﺎ وارد ﻣﺤﯿﻂ ﻣﯽﺷﻮﻧﺪ و ﻣﯽﺗﻮاﻧﻨﺪ ﺑﻪ زﻧﺠﯿﺮه ﻏﺬاﯾﯽ راه ﭘﯿﺪا ﮐﻨﻨﺪ. ﻣﻮاد و روش ﻫﺎ: در اﯾﻦ ﻣﻄﺎﻟﻌﻪ، ﺑﺎﮐﺘﺮيﻫﺎي ﻣﻘﺎوم ﺑﻪ ﮐﺮوم )VI( از ﻓﺎﺿﻼب ﺻﻨﻌﺘﯽ ﻣﺠﺘﻤﻊ ﻓﻮﻻد ﻣﺒﺎرﮐﻪ اﺻﻔﻬﺎن ﺟﺪاﺳﺎزي ﺷﺪﻧﺪ. ﺳﻮﯾﻪﻫﺎي ﺟﺪاﺳﺎزي ﺷﺪه، ﺷﻨﺎﺳﺎﯾﯽ ﺷﺪﻧﺪ و ﻣﯿﺰان ﻣﻘﺎوﻣﺖ آﻧﻬﺎ ﻧﺴﺒﺖ ﺑﻪ ﮐﺮوم ﺗﻌﯿﯿﻦ ﮔﺮدﯾﺪ و از ﺳﻮﯾﻪ اي ﮐﻪ ﺑﺎﻻﺗﺮﯾﻦ ﻣﻘﺎوﻣﺖ را ﺑﻪ ﮐﺮوم ﻧﺸﺎن داد ﺑﻪ ﻣﻨﻈﻮر ﺣﺬف زﯾﺴﺘﯽ ﮐﺮوم اﺳﺘﻔﺎده ﺷﺪ. روش ﺗﺠﺰﯾﻪوﺗﺤﻠﯿﻞ دادهﻫﺎ ﺑﺎ اﺳﺘﻔﺎده از آﻣﺎر ﺗﻮﺻﯿﻔﯽ و وارﯾﺎﻧﺲ ﯾﮏ ﻃﺮﻓﻪ ﯾﺎ ANOVA ﻣﯽﺑﺎﺷﺪ. ﯾﺎﻓﺘﻪﻫﺎ: ﻧﺘﺎﯾﺞ اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﻣﻨﺠﺮ ﺑﻪ ﺷﻨﺎﺳﺎﯾﯽ ﭘﻨﺞ ﺳﻮﯾﻪ ﻣﻘﺎوم ﺑﻪ ﻓﻠﺰ ﮐﺮوم ﺷﺪ ﮐﻪ ﺑﺎﮐﺘﺮيMicrococcus luteus SEHD031RSﺑﻪ دﻟﯿﻞ ﺣﺪاﻗﻞ ﻏﻠﻈﺖ ﺑﺎزدارﻧﺪﮔﯽ 140 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻟﯿﺘﺮ و ﺣﺪاﻗﻞ ﻏﻠﻈﺖ ﮐﺸﻨﺪﮔﯽ 152 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻟﯿﺘﺮ، ﺑﺮﺗﺮﯾﻦ ﺳﻮﯾﻪ ﻣﻘﺎوم ﺑﻪ ﮐﺮوم ﺷﻨﺎﺧﺘﻪ ﺷﺪ. در اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﺎﻻﺗﺮﯾﻦ ﻣﯿﺰان ﺣﺬف ﻓﻠﺰ ﮐﺮوم در4 =pH، ﻏﻠﻈﺖ30 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻟﯿﺘﺮ و ﻣﺪت زﻣﺎن 96 ﺳﺎﻋﺖ، 82/5 درﺻﺪ ﺣﺎﺻﻞ ﺷﺪ. ﻧﺘﯿﺠﻪﮔﯿﺮي: ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﻧﺸﺎن ﻣﯽ دﻫﺪ ﮐﻪ ﺳﻮﯾﻪ Micrococcus luteus SEHD031RS ﻣﯽ ﺗﻮاﻧﺪ ﺑﻪ ﻋﻨﻮان ﯾﮏ ﻣﯿﮑﺮوارﮔﺎﻧﯿﺴﻢ ﻣﺆﺛﺮ در ﺣﺬف ﮐﺮوم از ﻓﺎﺿﻼب ﻫﺎي ﺻﻨﻌﺘﯽ ﯾﺎ ﭘﺎك ﺳﺎزي ﻣﺤﯿﻂ اﺳﺘﻔﺎده ﺷﻮد.

Similar to some organic materials the heavy metals are not easily removed from the environment because of the toxic nature and form a class of stable and non-biodegradable pollutants. These elements enter the nature and the food chain as a result of natural activities such as eruptions of volcanoes and human activities such as mining, producing industrial and urban wastewaters and applying pesticides. Materials and Methods: In this study, chrome (VI) -resistant bacteria were isolated from the industrial wastewater taken from Isfahan Mobarakeh Steel Complex. The isolated strains were identified and their resistance to chromium was determined and the strain with the highest resistance to chromium was used for its bioremediation. Data were analyzed using descriptive statistics and one way ANOVA. Results: The results of this study led to the identification of five chrome resistant strains that the Micrococcus luteus SEHD031RS bacterium was detected as the best chrome resistant strain due to the minimum inhibitory concentration of 140 mgL-1 and minimum bactericidal concentration of 152 mgL-1. In this study, the highest chromium removal rate of 82.5% was obtained at pH 4, concentration of 30 mgL-1 and 96 hours. Conclusion: The results of this study indicate that the Micrococcus luteus SEHD031RS strain can be used as an effective microorganism in removing chromium from industrial wastewater or environmental bioremediation.