کارایی کیتوزان به‌همراه پلی‌آلومینیوم‌کلراید در حذف کدورت از آب ورودی به تصفیه‌خانه اهواز

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانش آموخته کارشناسی ارشد شیمی کاربردی، دانشگاه آزاد اسلامی، واحد امیدیه، اهواز

2 استادیار گروه مهندسی بهداشت محیط و عضو مرکز تحقیقات فناوری‌های زیست‌محیطی، دانشگاه علوم پزشکی جندی‌شاپور اهواز

3 استادیار گروه مهندسی شیمی، دانشگاه صنعتی امیرکبیر، تهران

4 مدیزیت کنترل کیفیت و نظارت بر بهداشت آب و فاضلاب اهواز

چکیده

کیتوزان یک پلیمر کاتیونی زیست تجزیه‌پذیر بوده که از دی‌استیلاسیون‌کیتین مشتق شده است. در این تحقیق با هدف بررسی اثر کیتوزان به‌عنوان کمک منعقدکننده در بهبود عملکرد منعقدکننده پلی‌آلومینیوم‌کلراید در حذف کدورت، از آب آشامیدنی صورت پذیرفت. این پژوهش در مقیاس آزمایشگاهی و با استفاده از دستگاه جارتست در تصفیه‌خانه آب اهواز انجام شد. آزمایش‌ها بر مبنای متغیرهایی چون غلظت ماده منعقدکننده، pH و نیز غلظت کیتوزان به‌عنوان کمک منعقدکننده صورت پذیرفت. نمونه‌ها پس از آماده‌سازی در دستگاه جارتست، تحت عمل اختلاط سریع با 120 دور در دقیقه به‌مدت 1 دقیقه و اختلاط آرام با سرعت 40 دور در دقیقه به‌مدت 20 دقیقه و همچنین مدت 30 دقیقه به‌منظور ته‌نشینی در شرایط سکون قرار گرفتند. pH بهینه برای حذف کدورت، در pH برابر 8 مشاهده گردید. دز بهینه پلی‌آلومینیوم‌کلراید به‌همراه کیتوزان، به‌ترتیب 5 میلی‌گرم در لیتر و 0/02 میلی‌گرم در لیتر به‌دست آمد. در شرایط بهینه کاربرد کیتوزان حدود 50 درصد غلظت منعقدکننده پلی‌آلومینیوم‌کلراید را کاهش داد. به علاوه، فلوک‌های تشکیل شده توسط کیتوزان درشت‌تر بوده و سرعت ته‌نشینی بالایی داشتند. نتایج تحقیق بیانگر کارایی خوب کیتوزان به‌عنوان کمک منعقدکننده در حذف کدورت از آب آشامیدنی است.

کلیدواژه‌ها


عنوان مقاله [English]

Efficiency of Chitosan with Polyaluminum Chloride in Turbidity Removal from Ahwaz Water Treatment Plant Influent

نویسندگان [English]

  • Naghmeh Orooji 1
  • Afshin Takdastan 2
  • Ali Kargari 3
  • Gholamreza Raeesi 4
1 Grad. M.Sc. Student of Applied Chemistry, Islamic Azad University, Omidieh Branch, Ahwaz
2 Assist. Prof. of Environmental Health Eng. and Member of Environmental Tech. Research Center, Jondishapur University of Medical Sciences, Ahwaz
3 Assist. Prof. of Chemistry Eng., Amirkabir University of Tech. Tehran
4 Management of Quality Control and Health Monitoring of Ahwaz Water and Wastewater
چکیده [English]

Chitosan, is a biodegradable cationic polymer, which is derived from deacetylation of chitin. The present study was conducted to investigate the effect of chitosan as a coagulant aids in improving the performance of coagulant property of poly-aluminum chloride as a primary coagulant on the removal of turbidity from water. This study, was performed in a laboratory scale and using jar test apparatus in Ahwaz Water Treatment Plant. Experiments were performed with different concentrations of coagulants, pH and different concentrations of chitosan as a coagulant aids. First the samples mixed under rapid mixing condition (120rpm) for 1minute and then the apparatus set to slow mixing (40rpm) for 20 minute. After mixing the samples left for 30 minute in order to settle the sediments. The optimum pH was found 8 in this study. The optimum doses of poly-aluminum chloride in conjunction with chitosan, were 5mg/L and 0.02 mg/L, respectively. The required dosage of poly-aluminum chloride as a primary coagulant be reduced upto 50% under optimum condition with chitosan. It was also found using chitosan also produced larger floc with higher settling velocity than primary coagulant alone. The results also showed that chitosan as a coagulant aid had a positive effect on turbidity removal.

کلیدواژه‌ها [English]

  • Coagulation
  • Turbidity
  • Chitosan
  • Polyaluminum Chloride
  • Water Treatment
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