Modares Civil Engineering journal
مهندسی عمران مدرس
MCEJ
Engineering & Technology
http://mcej.modares.ac.ir
1
admin
2476-6763
10.22034
fa
jalali
1395
3
1
gregorian
2016
6
1
16
2
online
1
fulltext
fa
مدلسازی و بهینه سازی فرایند حذف تولوئن از محلول های آبی با استفاده از نانو ذرات اکسید آهن به روش RSM
Modeling and optimization of removal of toluene from aqueous solutions using iron oxide nanoparticles by RSM method
در این تحقیق، از فرایند شبه فنتون برای حذف تولوئن از محلول های آبی با غلظت اولیه ppm100 استفاده شد. نانوذرات اکسید آهن با قطر حدود nm 18، از کاتالیست های مستعمل پتروشیمی تبریز با استفاده از آسیاب گلوله ای تهیه شد. کاتالیست های مستعمل و نانوذرات تهیه شده، توسط آنالیزهای BET، XRF، XRD و FE-SEM تعیین مشخصات شدند. برای تعیین غلظت تولوئن، از دستگاه کروماتوگرافی گازی (GC) استفاده شد. به منظور بررسی بر هم کنش پارامترهای تاثیرگذار [H2O2]/[Catalyst]، ]غلظت آلاینده [H2O2]/[و زمان واکنش (دقیقه) بر درصد حذف تولوئن و یافتن شرایط بهینه، طراحی آزمایش به روش RSM صورت گرفت و مقادیر بهینه برای این پارامترها به ترتیب 460/0، 928/4 و 7/105 بدست آمد. معادله درجه دوم با ضریب همبستگی بسیار بالایی برای پیش بینی حذف تولوئن برازش شد که مقادیر R2 و R2(adj) مدل پیش بینی شده، به ترتیب برابر با %14/99 و %37/98 توسط نرم افزار minitab حاصل شد. بر اساس آزمایش های انجام شده، در شرایط بهینه پارامترهای تاثیرگذار، حذف کامل تولوئن از محلول های آبی حاصل شد. نتایج حاصل از این پژوهش نشان داد که روش RSM ابزار مناسبی جهت مدلسازی و بهینه سازی فرایند شبه فنتون برای حذف تولوئن می باشد. همچنین نتایج نشان داد که نانوذرات اکسید آهن تهیه شده از کاتالیست های مستعمل پتروشیمی تبریز، قابلیت بسیار خوبی برای استفاده در فرایند شبه فنتون جهت حذف تولوئن از محلول های آبی دارند.
Toluene is a dangerous pollutant in aqueous solutions that should be removed completely. In this paper iron oxide nanoparticles were employed for removing of toluene from aqueous solutions with initial concentration of 100 ppm by Fenton-Like process. Iron oxide nanoparticles synthesised from spent catalysts of Tabriz Petrochemical Styrene Unit using a ball mill. these nanoparticles were characterized by BET, XRD, XRF and FE-SEM analysis. The milling of spent catalysts was performed in dry ball mill. Dry ball milling of spent catalysts was carried out in presence of argon as an inert gas. Iron oxide nanoparticles with diameter about 18 nm were obtained after 4 hours by dry ball milling of spent catalysts using 15 balls with a diameter of 20 mm. The milling was performed at a rotation speed of 400 rpm.The results of BET analysis showed that specific surface of catalysts has increased more than 9 times with the milling of spent catalysts. XRD patterns showed that during dry milling, some of Fe3O4 has converted to Fe2O3. Due to the higher rate of reaction of Fe2O3 compared to the Fe3O4 in Fenton process, this conversion causes higher rate of toluene elimination from aqueous solutions. The crystal size of spent catalysts and synthesized iron oxide nanoparticles was calculated by Scherrer equation. The crystal size of spent catalysts and synthesized iron oxide nanoparticles were obtained 56.6 nm and 33.9 nm respectively which confirmed the results of BET analysis. The concentration of toluene in aqueous solutions was measured by Gas Chromatography (GC-Agilent 7890A) equipped with FID detector and HP-Plot Q column (30m × 0.530 mm× 40.0 μm) using liquid-liquid extraction by hexane. Hexane and samples were mixed with volume ratio of 1/10. Samples were injected to GC in volume of 1 micro liter by a syringe (Agilent). Experiments were performed at pH=3 and room temperature (25◦C) in a batch reactor in volume of 500 ml with a mechanical stirrer. Due to study of interaction between the parameters and determining the optimal conditions, experimental design was performed by RSM method. [H2O2]/[Catalyst], [H2O2]/[concentration of pollution] and time (min) were considered as efficient parameters on removing of toluene. Quadratic equation with high correlation coefficient fitted using RSM method. R2 and R2(adj) values of predicted model for removing of toluene in Fenton-Like process were obtained 99.14% and 98.37% respectively. The results showed that [H2O2]/[Catalyst] and [H2O2]/[concentration of pollution] have optimum ranges. The optimum ranges for [H2O2]/[Catalyst] and [H2O2]/[concentration of pollution] were obtained 0.36-0.5 and 4-5.5 respectively . Optimal values for [H2O2]/[Catalyst], [H2O2]/[concentration of pollution] and time (min) for removing of toluene in Fenton-Like process were obtained 0.460, 4.928 and 105.7 respectively. In optimum conditions for efficient parameters, complete removal of toluene by Minitab software was predicted. Experiments in the optimum conditions also confirmed the results of Minitab software. The results showed that spent catalysts of Tabriz Petrochemical which are considered as waste, have a good ability for activation of H2O2 and removing of toluene from aqueous solutions. Keywords: Toluene, Aqueous solution, Fenton-Like, Iron oxide nanoparticles, Optimization.
تولوئن,شبه فنتون,نانوذرات اکسید آهن,محلول های آبی,بهینه سازی
Toluene,Aqueous solution,Fenton-Like,Iron oxide nanoparticles,Optimization
203
213
http://mcej.modares.ac.ir/browse.php?a_code=A-16-1000-8763&slc_lang=fa&sid=16
Nabi Allah
Gharibzadeh
نبی الله
غریب زاده
100319475328460060778
100319475328460060778
No
Sahand University of Technology
عضو مرکز تحقیقات مهندسی محیط زیست، دانشگاه صنعتی سهند تبریز
Esmaeil
Fatehifar
اسماعیل
فاتحی فر
100319475328460060777
100319475328460060777
Yes
Member of Environmental Engineering Research Center
عضو مرکز تحقیقات مهندسی محیط زیست
Reza
Alizadeh
رضا
علیزاده
100319475328460060776
100319475328460060776
No
Sahand University of Technology
عضو مرکز تحقیقات مهندسی محیط زیست، دانشگاه صنعتی سهند تبریز
Amirnaser
Haghlesan
امیرناصر
حق لسان
100319475328460060775
100319475328460060775
No
Sahand University of Technology
عضو مرکز تحقیقات مهندسی محیط زیست، دانشگاه صنعتی سهند تبریز
Mirmohammad
Chavoshbashi
میرمحمد
چاوش باشی
100319475328460060774
100319475328460060774
No
رئیس محیط زیست، شرکت پتروشیمی تبریز