نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده علوم پایه، دانشگاه آزاد اسلامی واحد مراغه، صندوق پستی: 47591-55197، مراغه - ایران

2 پژوهشکده چرخه سوخت هسته‌ای، پژوهشگاه علوم و فنون هسته‌ای، سازمان انرژی اتمی ایران، صندوق پستی: 8486-11365، تهران ـ ایران

3 گروه مهندسی شیمی، دانشکده فنی، دانشگاه تهران، صندوق پستی: 4563-11155، تهران - ایران

چکیده

خطرات زیست محیطی پساب‌های حاوی فلزات سنگین از جمله سرب، توجه پژوهشگران را برای پاک‌سازی آن‌ها با استفاده از روش‌های نوین مانند زیست پالایی متمرکز کرده است. در این مطالعه توانایی جذب زیستی سرب توسط باکتری Bacillus sp. strain STG-83 مورد ارزیابی قرار گرفت. از روش رویه پاسخ با طراحی مرکب مرکزی توسط نرم‌افزار دیزاین اکسپرت جهت بهینه‌سازی پارامترهایی چون pH، مقدار جاذب زیستی و غلظت اولیه سرب استفاده شد. نتایج نشان می‌دهد که مدل درجه دوم پیشنهاد شده توسط نرم‌افزار دیزاین اکسپرت با 9938/0=2R، به خوبی رفتار فرایند را پیش‌بینی کرده و جذب ‌زیستی در 5/4pH=، غلظت اولیه سرب 1-mg.L 95/297، مقدار جاذب 1- g.L1 بهینه می‌شود که برابر با dry weight 1- mg.g595/149 می‌باشد. هم‌چنین داده‌های تجربی با ایزوترم‌های لانگمویر و فروندلیچ برازش شد. نتایج نشان داد که مدل لانگمویر با 961/0=2R مناسب‌تر است. مطالعات سینتیکی نیز نشان داد که ظرفیت جذب در 5 دقیقه به بیش‌ترین مقدار خود می‌رسد. نهایتاً با توجه به پتانسیل ارزشمند این باکتری در جذب زیستی سریع و بالای سرب، Bacillus sp. strain STG-83 به عنوان یک جاذب باکتریایی با ارزشی جهت فرایندهای زیست پالایی سرب معرفی شده و کارایی روش رویه پاسخ در مدل‌سازی و بهینه‌سازی فرایند جذب زیستی سرب توسط باکتری مذکور تأیید می‌گردد.

کلیدواژه‌ها

عنوان مقاله [English]

Optimization of efficient lead removal by Bacillus sp. Strain STG-83 using response surface methodology for bioremediation of contaminated wastewater

نویسندگان [English]

  • S. Salimi 1
  • P. Tajer-Mohammad-Ghazvini 2
  • R. Dabbagh 2
  • E. Eivazi 3

1 Faculty of Basic Sciences, Maragheh Branch, Islamic Azad University, P.O.Box: 55197-47591, Maragheh - Iran

2 Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, AEOI, P.O.Box: 11365-8486, Tehran - Iran

3 Department of Chemical Engineering, Faculty of Engineering, University of Tehran, P.O.Box: 11155-4563, Tehran - Iran

چکیده [English]

Environmental hazards of wastewater containing metals, including lead, have attracted researchers' attention on their cleanup using novel methods such as bioremediation. In the present study, the biosorption ability of lead by Bacillus sp. Strain STG-83 was evaluated. Response surface methodology with central composite design by the Design Expert software was used to optimize parameters such as pH, biomass concentration, and initial lead concentration. The results showed that the quadratic model proposed by Design Expert software with a correlation coefficient of R2=0.9938 predicted the process behavior properly; lead biosorption by the bacteria was optimized at pH=4.5, initial concentration of lead 297.95 mg. L-1, and the amount of adsorbent 1 g.L-1, which is equal to 149.595 mg. g-1 dry weight. Also, the experimental data were fitted with Langmuir and Freundlich isotherms. The results showed that the Langmuir model is more suitable with R2=0.961. Kinetic studies showed that adsorption capacity reached its maximum value within 5 minutes. Ultimately, due to the valuable potential of this bacterium in rapid and high biosorption of lead, Bacillus sp. strain STG-83 is introduced as a valuable bacterial sorbent for lead bioremediation processes and performance of response surface methodology in modeling and optimizing lead biosorption process by Bacillus sp. strain STG-83 is confirmed.

کلیدواژه‌ها [English]

  • Bacteria
  • Biosorption
  • Bioremediation
  • Lead
  • Experiment design
1. J.D. Van Horn, H. Huang, Uranium (VI) bio-coordination chemistry from biochemical, solution and protein structural data, Coordination Chemistry Reviews, 250, 765-775 (2006).
 
2. M. Jansson-Charrier, et al, Dynamic removal of uranium by chitosan: influence of operating parameters, Water Science and Technology, 34, 169 (1996).
 
3. IAEA, Management of Problematic Waste and Material Generated During the Decommissioning of  Nuclear  Facilities, Technical  Reports  Series  No. 441, International  Atomic  Energy Agency, Vienna (2006).
 
4. A. Abdelouas, Uranium mill tailings: geochemistry, mineralogy, and environmental impact, Elements, 2, 335-341 (2006).
 
5. K. Thomas, Management of wastes from uranium mines and mills, Int. At. Energy Agency Bull, 23, 33-35 (1981).
 
6. L. Hajiaghababaei, et al, Highly efficient removal and preconcentration of lead and cadmium cations from water and wastewater samples using ethylene-diamine functionalized SBA-15, Desalination, 266, 182-187 (2011).
 
7. B. Volesky, Biosorption process simulation tools, Hydrometallurgy, 71, 179-190 (2003).
 
8. K. Vijayaraghavan, Y.-S. Yun, Bacterial biosorbents and biosorption, Biotechnology Advances, 26, 266-291 (2008).
 
9. P. Tajer-Mohammad-Ghazvini, et al, Cobalt separation by Alphaproteobacterium MTB-KTN90: Magnetotactic bacteria in bioremediation, Bioprocess and biosystems engineering, 39, 1899-1911 (2016).
 
10. B. Volesky, Sorption and Biosorption, Montreal-St. Lambert, Quebec, Canada, BV Sorbex Inc, 11, 258-263 (2003).
 
11. S. Schiever, Multi-metal ion exchange in biosorption, in, PhD. Thesis, Department of Chemical Engineering, McGill University, Montreal, (1996).
 
12. L. Eriksson, et al, Design of experiments, Principles and Applications, Learn ways AB, Stockholm, (2000).
 
13. M.J. Anderson, P.J. Whitcomb, RSM simplified: optimizing processes using response surface methods for design of experiments, Productivity Press, (2016).
 
14. M.R. Soudi, et al, Bioprocessing of seleno-oxyanions and tellurite in a novel Bacillus sp. strain STG-83: A solution to removal of toxic oxyanions in presence of nitrate, Journal of Hazardous Materials, 165,  71-77 (2009).
 
15. S. Ghorbanzadeh Mashkani, P. Tajer Mohammad Ghazvini, Biotechnological potential of Azolla filiculoides for biosorption of Cs and Sr: Application of micro-PIXE for measurement of biosorption, Bioresource Technology, 100, 1915-1921 (2009).
 
16. A. Witek-Krowiak, et al, Application of response surface methodology and artificial neural network methods in modelling and optimization of biosorption process, Bioresource Technology, 160, 150-160 (2014).
 
17. Y. Li, et al, Removal of copper from aqueous solution by carbon nanotube/calcium alginate composites, Journal of Hazardous Materials, 177, 876-880 (2010).
 
18. R. Kasra-Kermanshahi, M. Bahrami-Bavani, P. Tajer-Mohammad-Ghazvini, Microbial clean-up of uranium in the presence of molybdenum using pretreated Acidithiobacillus ferrooxidans, Journal of Radioanalytical and Nuclear Chemistry, 322, 1139-1149 (2019).
 
19. M. Malakootian, Z. Khodashenas Limoni, M. Malakootian, The efficiency of lead biosorption from industrial wastewater by micro-alga spirulina platensis, International Journal of Environmental Research, 10, 357-366 (2016).
 
20. S. Tunali, A. Cabuk, T. Akar, Removal of lead and copper ions from aqueous solutions by bacterial strain isolated from soil, Chemical Engineering Journal, 115, 203-211 (2006).
 
21. S.K. Sen, et al, Contribution of hot spring bacterial consortium in cadmium and lead bioremediation through quadratic programming model, Journal of Hazardous Materials, 265, 47-60 (2014).
 
22. X. Ma, et al, Efficient biosorption of lead (II) and cadmium (II) ions from aqueous solutions by functionalized cell with intracellular CaCO3 mineral scaffolds, Bioresource Technology, 185, 70-78 (2015).
 
23. A. Sarı, et al, Adsorption characteristics of Cu (II) and Pb (II) onto expanded perlite from aqueous solution, Journal of Hazardous Materials, 148, 387-394 (2007).
 
24. X. Xu, et al, A facile approach for surface alteration of Pseudomonas putida I3 by supplying K2SO4 into growth medium: Enhanced removal of Pb(II) from aqueous solution, Bioresource Technology, 232, 79-86 (2017).
 
25. G. Yuvaraja, et al, Biosorption of Pb (II) from aqueous solution by Solanum melongena leaf powder as a low-cost biosorbent prepared from agricultural waste, Colloids and Surfaces B: Biointerfaces, 114, 75-81 (2014).
 
26. A. Ronda, et al, Combustion of a Pb(II)-loaded olive tree pruning used as biosorbent, Journal of Hazardous Materials, 308, 285-293 (2016).
 
27. Y. Tang, et al, Removal of lead ions from aqueous solution by the dried aquatic plant, Lemna perpusilla Torr, Journal of Hazardous Materials, 244-245, 603-612 (2013).
 
28. F. Malekzadeh, et al, Biosorption of tungstate by a Bacillus sp. isolated from Anzali lagoon, World Journal of Microbiology and Biotechnology, 23, 905-910 (2007).