بررسی کارایی فرایند انعقاد الکتریکی- شناورسازی الکتریکی با الکترودهای آلومینیم - گرافیت نمدی در حذف باکتری‌های اشرشیاکلی و سالمونلا تیفی موریوم از آب آشامیدنی

نویسندگان

1 کارشناس بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی اردبیل، اردبیل، ایران

2 استاد یار گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی اردبیل، اردبیل، ایران.

3 دانشکده علوم پزشکی خلخال، عضو کمیته تحقیقات دانشجویی، دانشگاه علوم پزشکی اردبیل، اردبیل، ایران

4 ، دانشکده بهداشت، دانشگاه علوم پزشکی اردبیل، اردبیل، ایران

5 مربی گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی ارومیه، ارومیه، ایران.

چکیده

زمینه و هدف: انعقاد الکتریکی یک روش الکتروشیمیایی برای تصفیه آب است. هدف از انجام این تحقیق بررسی حذف باکتری­های اشرشیاکلی و سالمونلا تیفی موریوم به روش انعقاد الکتریکی-شناورسازی الکتریکی با الکترود­های آلومینیم- گرافیت نمدی به حالت تک قطبی موازی از آب آشامیدنی  می­باشد.
روش بررسی: متغیرهای مستقل فرآیند شامل سویه­های باکتریایی اشرشیاکلی و سالمونلا تیفی موریوم با غلظت­های مختلف باکتریایی (104، 105 و106 عدد در میلی­لیتر  (، زمان واکنش (5 ، 10،  15 و 20دقیقه)، pH اولیه (7، 8 و 9) فاصله بین الکترودها (1، 2 و 3 سانتی متر) و چگالی جریان (83/0، 67/1 و 5/2 میلی آمپر بر سانتی متر مربع) جهت تعیین شرایط بهینه  بررسی شد.
یافته‌ها: نتایج نشان می­دهد که در شرایط بهینه با افزایش pH از 7 به 9 راندمان حذف سویه­های باکتریایی اشرشیاکلی به طور معنی داری از100 به 83 % و سالمونلا تیفی موریوم از 100 به 90% کاهش پیدا می­کند. در غلظت اولیه 105 عدد باکتری در میلی­لیتر شرایط بهینه برای چگالی جریان، زمان واکنش و فاصله بین الکترودها بترتیب در 5/2 میلی آمپر بر سانتی متر مربع ، 20 دقیقه و 2 سانتی متر بدست آمد.
نتیجه‌گیری: بر طبق نتایج، راندمان حذف سویه­های باکتریایی اشرشیاکلی و سالمونلا تیفی موریوم در شرایط بهینه 100% بدست آمد. بنابراین می­توان از فرآیند انعقاد الکتریکی-شناورسازی الکتریکی در حذف باکتری­های بیماری­زای از آب آشامیدنی استفاده کرد.
 

کلیدواژه‌ها

عنوان مقاله [English]

Investigation of Electrocoagulation/Electroflotation Process Efficiency with Aluminum-Graphite felt Electrodes in Removal of E.coli and S. typhimurium from Drinking Water

نویسندگان [English]

  • soudabeh alizadeh 1
  • ahmad mokhrari 2
  • fariba jedi 3
  • fatameh ataei 3
  • tayyebeh sadeghi 4
  • esrafil asgari 5

1

2

3

4

5

چکیده [English]

Background: Water disinfection by electrochemical methods has been increasingly carried out recently. The aim of this applied research is to investigate the removal of E. coli and S. typhimurium bacteria from drinking water by using Electrocoagulation (EC) - Electroflotation (EF) with Aluminum- Graphite felt electrodes parallel with the monopole mode.
Methods: An experimental study was conducted in a batch system. In this study, the contaminated water samples were prepared through adding of E. coli and S. typhimurium bacteria with concentrations of 104, 105 and 106 CFU/ml. Independent variables Included: different concentrations of E.coli and S. typhimurium bacteria (104, 105 and 106 CFU/mL), reaction time (5, 10, 15 and 20 min), initial pH (7, 8 and 9), electrode gap (1, 2 and 3 cm), current density (0.83, 1.67 and 2.5 mA/cm2) to determine the optimum conditions were investigated.
Results: The results show that in the optimum conditions with increasing the pH from 7 to 9 removal efficiency of bacterial strains of E.coli and S. typhimurium were decreased significantly from 100 to 83% and 100 to 90%, respectively. In initial concentration of 105 CFU/mL, optimum conditions were obtained for current density, reaction time and electrodes gap; 2.5 mA/cm2, 20 min and 2 cm, respectively. With increasing current density and reaction time in both strains of bacteria, were decreased significantly. The electrodes gap do not have much impact on the efficiency of the process. The amount of electrical energy consumed in optimal conditions was calculated 1/8172 KWh/m3.
 

کلیدواژه‌ها [English]

  • electrocoagulation
  • Electroflotation
  • E. coli
  • S. typhimurium
  • Drinking water
  • Disinfection
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