An experimental investigation of proxy electrocoagulation process efficiency for COD removal from Azithromycin contaminated aqueous solution

Background and Aims: Pharmaceuticals are considered as emerging environmental pollutants due to their continuous input and persistence in the aquatic ecosystem even at low concentrations. This work focuses on the removal of chemical oxygen demand (COD) from Azithromycin contaminated synthetic aqueous solution through proxy electrocoagulation process.Materials and Methods: A batch method was used for removal of Azithromycin from water. The parameters affecting on the proxy electrocoagulation of antibiotics and subsequently COD removal efficiency such as reaction time, concentration of hydrogen peroxide, current density and pH of the solution was investigated.Results: The proxy electrocoagulation process achieved a very high COD removal efficiency (95.6%) with reaction time of 60 min, current density of 20 mA/cm-2 and at pH 3 in the presence of 1.5 mg/L of hydrogen peroxide, producing cleaned water.Conclusion: Although economically should be investigated compared to other methods, the studied process was useful in terms of Azithromycin removal from aqueous solutions.Key words: Wastewater, electrocoagulation, Azithromycin, CO

Evaluation of sugar bagasse efficiency in phenol removal from aqueous solutions

اهداف و زمینه: ترکیبات فنولیک موجود در آب دارای اثرات زیان آور برای سلامتی و محیط زیست بوده و مزه ناخوشایندی در آب آشامیدنی ایجاد میکند، به همین جهت جاذب های متعددی برای حذف فنول از آب پیشنهاد شده است. هدف این مطالعه بررسی کارایی باگاس نیشکر جهت حذف فنول از محلولهای آبی میباشد مواد و روشها: باگاس تهیه شده پس از آماده سازی و اضافه نمودن مقادیر مشخص فنول، در بازههای زمانی معین توسط سانتریفیوژ از محلول جدا شده و میزان جذب محلول باقیمانده توسط دستگاه اسپکتروفتومتر خوانده شد. تحلیل داده ها بوسیله نرم افزارهای EXCEL2010 و PRISM6 صورت گرفت. موازین اخلاقی مربوط به روش کار و استفاده از منابع رعایت گردید یافته ها: با افزایش pH وغلظت اولیه فنول راندمان جذب کاهش یافت. همچنین با افزایش مقدار جاذب و مدت زمان تماس راندمان جذب افزایش یافت. شرایط بهینه برای حذف فنل pH برابر 3، غلظت باگاس 2 g/L و زمان 50 دقیقه و ظرفیت جذب توسط باگاس برابر16 mg/g بدست آمد. آنالیز داده های تجربی با مدلهای جذب فرندلیچ و لانگمویر به ترتیب دارای ضریب همبستگی 0.9755و 0.8359میباشد نتیجه گیری: نتایج این مطالعه نشان داد با فراهم نمودن شرایط بهینه، میتوان از باگاس بعنوان یک جاذب آلی برای حذف مناسب فنول استفاده نمود. بنابراین با توجه به اینکه ضایعات باگاس در مقادیر زیادی در فراوری تهیه شکر تولید میشود، میتوان از آن به عنوان یک جاذب ارزان قیمت استفاده نمود.Background and Aims: Phenolic compounds in water and wastewater not only have deleterious effects on human health and ecosystem, but also change water flavor. Various adsorbents have therefore been suggested for phenol removal from water. In this article, the adsorptive removal of phenol from aqueous solutions by sugar bagasse was investigated.Material and Methods: Prepared bagasse was activated and certain amount of phenol was added on it, tubes were centrifuged in certain time intervals, then the bagasse removed from solution. Following adsorbent, the solution was centrifuged and the prepared bagasse were separated from the solution at certain time intervals.Residual solution was analyzed with UV spectrophotometer for remaining phenol concentrations. Data were analyzed using EXCEL2010 and PRISM6 software. All ethical issues have been considered throughout the study.Results: The results showed that phenol adsorption by the sugar bagasse decreased with increase in pH and initial phenol concentration, while it was decreased with increase in adsorbent dose, contact time, and temperature. In 10 and 20 mg/L of phenol concentration, a high removal efficiency (≥ 50 %) was observed.The optimal condition adsorption of phenol were suitable pH=3, adsorbent dosage=2 g and contact = 50 min. The maximum adsorption capacity was also 16mg/g. Experimental data were analyzed with Freundlich and Langmuir isotherm models and the correlation coefficients were 0.9755 and 0.8359, respectively.Conclusion: Bagasse, as a new adsorbent, could effectively remove phenol in optimal conditions. The adsorption isotherm was best fitted by Freundlich adsorption model