نوع مقاله : مقاله پژوهشی

نویسندگان

1 دکتر، گروه محیط‌زیست، دانشکده منابع طبیعی و علوم دریایی، دانشگاه تربیت‌مدرس، تهران، ایران.

2 استادتمام، گروه بهداشت محیط، دانشکده علوم پزشکی، دانشگاه تربیت‌مدرس، تهران، ایران.

3 دانشیار، گروه محیط‌زیست، دانشکده منابع طبیعی و علوم دریایی، دانشگاه تربیت‌مدرس، تهران، ایران.

4 استادتمام، گروه شیمی، دانشکده علوم پایه، دانشگاه تربیت‌مدرس، تهران، ایران.

10.21859/sums-2306836

چکیده

اهداف مهم‌ترین شاخص مؤثر در جذب آلاینده‌های فرّار از هوا، نوع جاذب است. به‌کارگیری جاذبی گزینش‌پذیر، به حذف آلاینده با هزینه کمتر و کارایی بیشتر منجر می‌شود. در این تحقیق، کارایی جاذب اکسیدمنگنز پوشانده‌شده بر سطح کربن فعال (MnO/GAC) برای حذف تولوئن از هوا بررسی شد. همچنین کارایی جاذب MnO/GAC در شرایط آزمایشی یکسان با کربن فعال ساده مقایسه شد.
مواد و روش ها جاذب MnO/GAC با روش سل‌ژل تولید شد. زمان‌ماند (5/0، 1، 5/1، 2 و 4 ثانیه) و غلظت تولوئن ورودی (100، 200، 300 و 400 ppmv) و دمای هوای ورودی (25، 50، 75 و 100 درجه سانتی‌گراد)، به‌عنوان شاخص‌های عملکردی مؤثر بر فرایند جذب آزمایش شد. کارایی جاذب‌های GAC و MnO/GAC براساس زمان نقطه شکست و ظرفیت جذب تعیین شد.
یافته ها زمان نقطه شکست جاذب MnO/GAC درمقایسه‌با GAC در زمان‌های ماند 5/0 تا 4 ثانیه، 6 تا 11درصد افزایش یافت. افزایش غلظت تولوئن ورودی از 100 به 400 ppm، زمان نقطه شکست را کاهش و ظرفیت جذب را به‌ترتیب به‌میزان 57/9 و 67/9درصد برای GAC و 59/6 و 61/1درصد برای MnO/GAC افزایش داد. افزون‌براین افزایش دمای هوای ورودی به رآکتور از 25 به 100 درجه سانتی‌گراد، زمان نقطه شکست جاذب GAC را از 41 به 26 ساعت کاهش داد. کارایی جاذب MnO/GAC، با افزایش دما رابطه مستقیم داشت؛ به‌طوری‌که زمان شکست ستون از 46 به 57 ساعت افزایش یافت.
نتیجه گیری نتایج نشان داد که جاذب MnO/GAC می‌تواند به‌عنوان جایگزین مناسبی برای GAC در جذب ترکیب‌های فرّار از جریان هوا به‌کار گرفته شود.

کلیدواژه‌ها

عنوان مقاله [English]

Comparison Between the Efficiency of Plain GAC and Supported GAC With Manganese Oxide for Toluene Adsorption From Waste Air Stream

نویسندگان [English]

  • Fatemeh Rezaei 1
  • Seyed Gholamreza Moussavi 2
  • Alireza Riyahi Bakhtiari 3
  • Yadollah Yamini 4

1 PhD., Department of Environment, Faculty of Natural Resources & Marine Sciences, Tarbiat Modares University, Tehran, Iran.

2 Full Professor, Department of Environmental Health, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.

3 Associate Professor, Department of Environment, Faculty of Natural Resources & Marine Sciences, Tarbiat Modares University, Tehran, Iran.

4 Full Professor, Department of Chemistry, Faculty of Basic Sciences, Tarbiat Modares University, Tehran, Iran.

چکیده [English]

Objectives Type of adsorbent is the most important parameter to adsorb volatile organic compounds (VOCs) from the air stream. Application of a selective adsorbent could lead to the higher efficiency and lower costs in the adsorption processes. The current study aimed at investigating the efficiency of manganese oxide impregnated on GAC support (MnO/GAC) to remove toluene from air stream. The efficiency of MnO/GAC and GAC absorbents for toluene removal were compared at the same experimental conditions.
Methods The MnO/GAC preparation method was Sol-gel. Retention time (0.5, 1, 1.5, 2, and 4 seconds), inlet toluene concentration (100, 200, 300, and 400 part per million, by volume) and the temperature of the air stream (25, 50, 75, and 100˚C) were examined as the main functional parameters in the adsorption process.
Results Breakthrough time of MnO/GAC adsorbent in comparison to that of the plain GAC increased 6% to 11% at the retention time of 0.5 to 4 seconds. Adsorption capacity of GAC and MnO/GAC increased 67.9% and 61.1% by increasing inlet toluene concentration from 100 to 400 ppmv, respectively. Breakthrough time of GAC and MnO/GAC decreased 57.9% and 59.6% by increasing inlet toluene concentration from 100 to 400 ppmv, respectively. Breakthrough time of GAC decreased from 41 to 26 hours by increasing the temperature of the air stream from 25˚C to 100˚C. Direct air temperature increase affected the MnO/GAC efficiency for toluene adsorption and the breakthrough time increased from 46 to 57 hours.
Conclusion Results of the current study showed that MnO/GAC could be applied as a good substitution for GAC in the adsorption of VOCs from air streams.

کلیدواژه‌ها [English]

  • Absorption
  • Toluene
  • Manganese Oxide
  • activated carbon
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