بررسی تأثیر پرمنگنات پتاسیم بر کارایی کیتوزان در کاهش کدورت و کلیفرم‌های فاضلاب

نوع مقاله: مقاله پژوهشی

نویسندگان

1 استادیار گروه بهداشت محیط ، دانشکده بهداشت ، دانشگاه علوم پزشکی تهران

2 عضو هیئت علمی گروه مهندسی بهداشت محیط، دانشکده بهداشت و پیراپزشکی آرادان، دانشگاه علوم پزشکی سمنان، سمنان

3 دانشجوی دکترای تخصصی مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی تهران

چکیده

کیتوزان به‌عنوان منعقدکننده‌ در تصفیه آب و فاضلاب نه تنها دارای عملکرد قابل مقایسه‌ای با منعقدکننده‌های رایج است بلکه بسیاری از معایب آنها را نیز ندارد. با این حال دارای خاصیت باکتری‌کشی ضعیف‌تری نسبت به آنها است. در این تحقیق اثر سینرژیستی پرمنگنات پتاسیم به‌عنوان یک ماده اکسید کننده قوی، بر میزان غیرفعال‌سازی کلیفرم‌های گوارشی و حذف کدورت توسط کیتوزان مورد بررسی قرار گرفت. نمونه فاضلاب سنتتیک با مخلوط کردن بنتونیت با آب خام و اضافه کردن محیط کشت خالص کلیفرم‌های گوارشی، آماده گردید. پس از آماده‌سازی نمونه سنتتیک فاضلاب و تعیین کدورت و انجام کشت میکربی برای تعیین تیتر اولیه کلیفرم‌های گوارشی، دزهای مختلف کیتوزان و پرمنگنات پتاسیم به‌صورت مجزا و ترکیبی طی آزمایش جار به آن تزریق گردید. سپس میزان حذف کدورت و کلیفرم‌های گوارشی تعیین و مورد ارزیابی قرار گرفت. استفاده همزمان از این دو ماده باعث افزایش میزان حذف کدورت و کلیفرم‌های گوارشی گردید. در بیشترین دز ترکیبی مورد استفاده (3 میلی‌‌گرم در لیتر کیتوزان و 5/1 میلی‌گرم در لیتر پرمنگنات پتاسیم) میزان کلیفرم‌های گوارشی به کمتر از MPN/100mL 100 کاهش یافت که معادل 4 لگاریتم حذف بود. استفاده ترکیبی از پرمنگنات پتاسیم و کیتوزان در تصفیه سوم فاضلاب می‌تواند کیفیت میکربی پساب را تا حد بسیار بالایی افزایش دهد که این امر سبب کاهش میزان مواد گندزدا می‌شود و در نتیجه در مرحله گندزدایی مواد جانبی کمتری تولید خواهد شد.

کلیدواژه‌ها


عنوان مقاله [English]

Effect of Potassium Permanganate on Effectiveness of Chitosan in Removing of Turbidity and Fecal Coliforms from Wastewater

نویسندگان [English]

  • Ramin Nabizadeh 1
  • Reza Nemati 2
  • Hasan Aslani 3
1 Assist. Prof. of Environmental Health, Faculty of Public Health, Tehran University of Medical Sciences, Tehran
2 Fauclty Member of Environmental Health Eng., Aradan Fauclty of Health and Paramedical, Semnan University of Medical Sciences, Semnan
3 Ph.D. Student of Environmental Health, Faculty of Public Health, Tehran University of Medical Sciences, Tehran
چکیده [English]

Chitosan, as a coagulant is used in water and wastewater treatment. It has similar performance in comparison with other conventional coagulants, and doesn’t have any disadvantages of them. However, its bactericidal property is lower than the metal based coagulants. In this study the potential synergistic effect of potassium permanganate, as a powerful oxidant, on the Chitosan fecal coliforms inactivation and turbidity removal has been investigated. Synthetic wastewater samples were prepared by mixing tap water with Bentonite and adding pure culture of fecal coliforms that provided by biological laboratory of Tehran University of Medical Sciences. After preparing synthetic samples of the wastewater and determining its turbidity and fecal coliforms concentration, various doses of Chitosan and Potassium Permanganate individually and in combination with each other, were injected to the samples. Afterwards supernatant of jar reactors were investigated for turbidity and fecal coliforms removal. Simultaneous use Chitosan and potassium permanganate has higher removal efficiency than the individual using of them. Highest applied combined dose (3 mg / L  Chitosan and 1.5  mg / L  potassium permanganate) reduced fecal coliform to a level less than 100 MPN/100mL , which is  equivalent 4 log-inactivation of fecal coliforms. Simultaneous use of Chitosan and potassium permanganate in tertiary treatment of wastewater can led to produce lower turbidity, as well as higher microbial quality in the effluent, which can reduce the amount of required disinfectant, consequently disinfection by products formation lowered very much.

کلیدواژه‌ها [English]

  • Chitosan
  • Potassium permanganate
  • Coagulation
  • Turbidity
  • Fecal Coliforms
  • Wastewater
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