fa بهینه‌سازی فرآیند حذف پروپیلن در یک راکتور لجن فعال متعارف به کمک روش تحلیل آزمایشات تاگوچی مقاله پژوهشی Original Research Article <p>Background and Objective: Exposure to propylene glycol can lead to many health risks on blood, skin and kidney. Biodegradation of synthetic wastewater containing propylene glycol was studied in a continuous conventional activated sludge bench scale reactor. Optimum conditions of microorganisms&#39; growth for biodegradation of propylene glycol were determined by Taguchi method. Materials and Methods: Primary microorganisms for start up of the bioreactor were obtained from sludge return line of a municipal wastewater treatment plant and adapted to different concentrations of propylene glycol in a conventional activated sludge reactor. Optimum growth conditions of microorganisms and also operational conditions of the system including pH, influent COD, source of nitrogen and salinity were determined in three levels by Taguchi method. Results: COD removal efficiency in conventional activated sludge reactor for influent concentrations of 400, 700, 900, 1100 and 1300 mg/L were 98%, 95%, 95%, 90% and 85% respectively. Optimization of the process by Taguchi method showed that source of nitrogen urea, pH = 8, salinity of 8% and influent COD of 1300 mg/L with importance priority of 41%, 25%, 17.11% and 16.142% were as optimum growth conditions of microorganisms and also operational conditions of the system for propylene glycol biodegradation respectively. Conclusion: According to the results obtained from this work, it can be concluded that optimum conditions of biological processes and improvement the efficiency of bioreactors can simply be done by the use of such experimental designs.</p> Key words: Propylene glycol, Conventional activated sludge, Wastewater treatment, Taguchi method 21 34 http://journal.zums.ac.ir/browse.php?a_code=A-10-4-497&slc_lang=fa&sid=1 Mehdi farzadkia مهدی فرزادکیا Sahand359@yahoo.com 5200319475328460060428 5200319475328460060428 No Dept. of Environment and Occupational Health, Tarbiat Modares University, Tehran, Iran Sahand Jorfi سهند جرفی 5200319475328460060429 5200319475328460060429 Yes Dept. of Environmental Health Engineering, Faculty of Health, Iran University of Medical Sciences, Tehran, Iran Roshanak Rezaei Kalantary روشنک رضایی کلانتری 5200319475328460060430 5200319475328460060430 No Dept. of Civil Engineering and Environment, Jami Institute of Technology, Tehran, Iran. Amir Reza Talaie امیررضا طلایی 5200319475328460060431 5200319475328460060431 No Fars Province Industerial Complex, Shiraz, Iran MohammadMehdi Mehrabani محمدمهدی مهربانی 5200319475328460060432 5200319475328460060432 No Dept. of Environmental Health Engineering, Faculty of Health, Iran University of Medical Sciences, Tehran, Iran