COD removal and decolorization efficacy of ozonation process in spiral high pressure super mixing reactor for treatment of alcohol distilleries wastewater

Background and Aims: Alcohol distillery wastewater is a highly polluted wastewater which its treatment poses a special problem. In this work, the efficiency of ozonation process exploited in a spiral high pressure super mixing reactor was studied for COD removal and decolorization of alcohol distilleries wastewater. The results was also compared with a conventional reactor. Materials and Methods: The present laboratory-scale research was done on real effluent from anaerobic wastewater treatment unit of alcohol wastewater. Experiments were conducted in a pressurized spiral super mixing reactor equipped with static mixers and also in a control conventional reactor with the same volume. The process performance criteria, such as COD, BOD and color, were determined according to standards methods for water and wastewater examination. Results: The pressurized spiral super mixing reactor showed high efficiency in removing pollutants and reducing ozone consumption as compared to conventional reactor. Typically, during 30 min, and pH =5.3, the COD removal efficiency in the pressurized spiral super mixing reactor was 4.8 times higher than that of conventional reactor. According to the results, the efficacy of ozonation process increased by changing the pH from acidic to alkaline. Generally, the respective highest removal efficiency of COD and color was obtained at pH=11 and pH=5.3  in both reactors at their maximum retention time.  Also the biodegradability of wastewater (BOD/COD) was enhanced in both reactors following ozonation process. Conclusion: The pressurized spiral super mixing reactor performance in reducing ozone consumption highlights the potential applicability of this reactor for wastewater treatment of alcohol industry. The reactor can be used as pre-treatment or post treatment processes for the appropriate treatment of industrial wastewater. Keywords: Ozone, Alcohol industry, Pressurized spiral super mixing reactor, Colour, CO

کارایی فرایند ازن ‌زنی در راکتور مارپیچی با اختلاط بالا جهت حذف COD و رنگ از فاضلاب صنعت الکل‌سازی

Background and Aims: Alcohol distillery wastewater is a highly polluted wastewater which its treatment poses a special problem. In this work, the efficiency of ozonation process exploited in a spiral high pressure super mixing reactor was studied for COD removal and decolorization of alcohol distilleries wastewater. The results was also compared with a conventional reactor.  Materials and Methods: The present laboratory-scale research was done on real effluent from anaerobic wastewater treatment unit of alcohol wastewater. Experiments were conducted in a pressurized spiral super mixing reactor equipped with static mixers and also in a control conventional reactor with the same volume. The process performance criteria, such as COD, BOD and color, were determined according to standards methods for water and wastewater examination.  Results: The pressurized spiral super mixing reactor showed high efficiency in removing pollutants and reducing ozone consumption as compared to conventional reactor. Typically, during 30 min, and pH =5.3, the COD removal efficiency in the pressurized spiral super mixing reactor was 4.8 times higher than that of conventional reactor. According to the results, the efficacy of ozonation process increased by changing the pH from acidic to alkaline. Generally, the respective highest removal efficiency of COD and color was obtained at pH=11 and pH=5.3  in both reactors at their maximum retention time.  Also the biodegradability of wastewater (BOD/COD) was enhanced in both reactors following ozonation process.  Conclusion: The pressurized spiral super mixing reactor performance in reducing ozone consumption highlights the potential applicability of this reactor for wastewater treatment of alcohol industry. The reactor can be used as pre-treatment or post treatment processes for the appropriate treatment of industrial wastewater.زمینه و اهداف: فاضلاب صنعت الکل‌سازی دارای آلودگی بسیار بالا و تصفیه آن مشکل می‌باشد. در این تحقیق کارایی فرایند ازن‌ زنی در راکتور مارپیچ و تحت فشار و اختلاط بالا با استفاده از استاتیک میکسر و مقایسه کارایی آن با راکتور متداول ازن ‌زنی به منظور تصفیه فاضلاب صنعت الکل‌سازی مورد بررسی قرار گرفته است.  مواد و  روش‌ها: این تحقیق بر روی پساب خروجی از واحد تصفیه بی‌هوازی فاضلاب واقعی حاصل از کارخانه الکل‌سازی در مقیاس آزمایشگاهی انجام شد. اکسیژن موردنیاز شیمیایی (COD)، اکسیژن موردنیاز بیوشیمیایی (BOD) و رنگ، آلاینده­های مورد بررسی بودند.  یافته‌ها: نتایج حاصل از این مطالعه نشان داد که راکتور مارپیچی با اختلاط بالا در شرایط کاملا مشابه نسبت به راکتور متداول، کارایی بیشتری در حذف آلاینده‌ها و کاهش مصرف میزان ازن دارد. به‌طوری‌که در زمان ماند 30 دقیقه و pH برابر 3/5 راندمان حذف COD در راکتور مارپیچی با اختلاط بالا، 8/4 برابر راکتور متداول بود. بیشترین راندمان حذف برای شاخص COD در هر دو راکتور مارپیچی با اختلاط بالا و معمول در حداکثر زمان ماند فرایند در pH برابر ۱۱ و برای رنگ در حداکثر زمان ماند فرایند در pH برابر ۳/۵ حاصل شد. همچنین نتایج نشان‌دهنده افزایش نسبت BOD/COD در هر دو راکتور در اثر فرایند ازن‌ زنی بود.  نتیجه‌گیری: کارائی راکتور مارپیچی با اختلاط بالا با استفاده از استاتیک میکسر، نشانگر قابلیت کاربرد این راکتور براي تصفيه فاضلاب صنعت الکل‌سازی مي‌باشد. همچنین می‌توان این راکتور را به عنوان پیش‌تصفیه و یا تصفیه پیشرفته فرایندهای بیولوژیکی جهت تصفیه بسیاری از فاضلاب‌های صنعتی مورد استفاده قرار داد