Evaluation of Microbiological Water Quality and Coastal Waters Quality Index of Persian Gulf in Bandar Abbas Coastal City, Iran

The goals of this study were to assess the microbiological quality and coastal water quality index (CWQI) in the Persian Gulf alongshore of Bandar Abbas city. Water samples were collected from five different coastal sites in spring and summer seasons. To assess the microbiological quality: Total Coliforms, Fecal Coliforms, Fecal Streptococci and Clostridium perfringens were measured. Also, eight physicochemical parameters (DO, BOD, TSS, Turbidity, Temperature, pH, Nitrate, Phosphate) were examined for calculating the CWQI. The mean for microbiological indicators was respectively, 3667, 1055, 50, 211 MPN/100ml. for physicochemical parameters, the average of water temperature was 32 °C, electrical conductivity was 57mmho/cm, the turbidity was 70.7 NTU, pH 8.1, and also the average concentration of phosphate, nitrate, nitrite, and ammonium was 180, 18.2, 4.9, 12.16μmol/L, and the mean of concentration BOD, COD and DO were 4.89, 11 and 6.8mg/L, respectively. In addition, the water quality index for all months and at selected stations was 65. The results showed that in the most samples the levels of microbiological indicators were exceeded the national standard and guideline values. Also, the computed CWQI showed that quality of water was weak. All the extracted results are closely related to the inlets connected to the sea. These inlets except the Ghadir station will affect the rest of the stations. In general, in low tide, the Bactria index was more than high tide

Removal of Ibuprofen from aqueous solutions by Ozonation process

AbstractBackground and Aims: Ibuprofen (IBU) is one of the most consumed nonsteroidal anti-inflammatory drugs (NSAIDs) widely used in musculoskeletal and analgesic treatments. This study set out with the aim of assessing the efficiency of conventional ozonation process in a semi-batch plug-flow reactor in order to remove IBU fromaqueous solutions.Materials and Methods: A laboratory scale semi-batch plug-flow ozonation reactor was employed during the present study. Four variables including pH, dosage of ozone, hydraulic retention time (HRT), and initial Ibuprofenconcentration, which might affect the degradation of Ibuprofen, were taken into consideration. The IBU concentration was determined using HPLC.Results: Working under optimal operating conditions (pH = 8, HRT = 60 min, C=5 mg/L and Ozone dose 2/5 g/h), about 59% IBU degradation was noticed. Results also revealed that the degradation of IBU well fitted with the firstorderkinetics.Conclusion: The operating variables of pH, dosage of ozone, initial Ibuprofen concentration, and HRT were optimized using a plug-flow reactor to improve contact between dissolved ozone and the drug. pH and HRT were the most affecting variables. Furthermore, a predictive model allowing us to predict the percentage of IBP degradationas a function of pH and HRT under experimental conditions was obtained.Keywords: Non-steroidal anti-inflammatory drugs, Ibuprofen, Ozonation, Hydraulic retention timeFor downloading the full text please click here

Optimization of coagulation-flocculation process for dye and COD removal from real dyeing wastewater and evaluation of effluent biodegradability in a carpet factory

Background and Aim: Textile industry is one of the largest consumers of water in the world. The wastewater from the textile industry is known to have strong colour, chemical oxygen demand (COD), highly fluctuating pH and high temperature. The release of coloured wastewater represents a serious environmental and public health concern. Among the various physicochemical and biological methods of textile wastewater treatment, coagulationflocculation is considered as an attractive and favourable technique because of its low cost, easy operation and highefficiency.Materials and methods: The study was conducted in the laboratory scale using Jar test. Dye removal from real wastewater was investigated by the use of three mineral coagulants including poly aluminum chloride, ferric sulfate and ferric chloride. In order to optimize the process, parameters including pH, coagulant dose, time and speed of coagulation were considered. Treated samples were analysed to determine the residual color and COD.Results: According to the results of our experiments, under optimum conditions of process (pH 9, doses of 250 mg/lcoagulant and coagulation speed of 175 rpm with a duration of 5 minutes), the highest removal efficiencies (COD 44.4% and color 95%) were obtained by the use of poly aluminum chloride. The results showed that poly aluminum chloride enhanced the biodegradability of wastewater from 0.07 to 0.21 at optimized process conditions.Conclusion: Although the coagulation process reduced a large percentage of pollution load in the wastewater, another process has to be followed to meet the wastewater discharge standards in receiving sources.Keywords: Textile wastewater, Dye, Coagulation, Biodegradabilit

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

Enhanced Biodegradation of Formaldehyde Using Aerobic Sequencing Batch Rotating Bed Bioreactor With and Without Stimulation by Hydrogen Peroxide

The removal of formaldehyde as a toxic substance from aqueous solutions is of particular importance. In this research, a sequencing batch rotating-bed bioreactor (SBRB) was used on a laboratory scale for biodegradation of formaldehyde from synthetic wastewater. The reactor was made of plexiglas with a cylindrical shape. Kaldnes media were placed in a rotating cylindrical basket in the reactor. The effects of formaldehyde concentration (500–1500 mg/L), hydraulic retention time (HRT) (8, 15, 24 hours), and injection of hydrogen peroxide (0.1-0.5 mM) on the performance of the reactor were investigated. The results showed that in the SBRB, at an HRT of 24 hours and an inlet formaldehyde concentration of 1000 mg/L, the removal efficiencies of formaldehyde and chemical oxygen demand (COD) were 99.2% and 92%, respectively, while without rotating the bed, the removal efficiency of formaldehyde and COD was found to be 95% and 83%, respectively. By adding hydrogen peroxide at a concentration of 0.3 mM and operation of the SBRB with an HRT of 8 hours and an inlet formaldehyde concentration of 1000 mg/L, an improvement in the removal efficiency of formaldehyde and COD (4% and 22%, respectively) was observed. Accordingly, SBRB stimulation with hydrogen peroxide could be considered as a high-performance process for the removal of formaldehyde and corresponding COD at a short HRT

Performance of electrical stimulated anaerobic baffled reactor for removal of typical pollutants from low-strength municipal wastewater at low temperatures

Background: Although anaerobic system has been successfully used for treating the strong industrial wastewater, its efficiency for low-strength wastewater as municipal wastewater is not satisfying. This study aimed to enhance the capability of an anaerobic baffled reactor (ABR) for treating municipal wastewater. Methods: A 7-L ABR with 5 compartments was operated for a 287-day period fed with primary effluent from a wastewater treatment plant at 17 to 19°C. The study was conducted in 2 phases. In the first phase, the performance of ABR and in the second phase, the performance of ESABR (ABR integrated with an electrochemical system) were investigated. Results: The results of ABR operation indicated that at hydraulic retention time (HRT) =24 hours, the average removal efficiency of biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total Kjeldahl nitrogen (TKN), total phosphorous (TP), and log reduction value (LRV) of coliforms were obtained to be 71%, 75%, 79%, 23%, 30.3%, and 5.8 Log, respectively. In this phase, when the HRT was decreased from 24 to 18 hours and from 18 to 14 hours, the removal efficiency of all parameters by the ABR was decreased. After the shift of ABR operation to ESABR, at HRT=24 hours and current density of 0.78 mA/cm2, the performance of the reactor was enhanced, so that the removal efficiency of BOD, COD, TSS, TKN, TP, and LRV of coliforms were achieved 16.8%, 15%, 4%, 10.7%, 49%, and 1 Log, which was greater than those obtained by ABR. Conclusion: According to the results, this technology (SEABR) is suitable for treating the low-strength municipal wastewater. Keywords: Wastewater, Anaerobic baffled reactor, Electrical stimulated, Treatmen

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

بررسی کارآیی فرآیند پراکسی الکتروکواگولاسیون در حذف COD آنتی‌بیوتیک آزیترومایسین از فاضلاب

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.چكيده زمينه و هدف: ورود داروها و باقیمانده‌های دارویی به محیط‌های آبی و پایداری آنها در محیط به عنوان یک مساله مهم در محیط زیست مطرح می‌باشد. هدف از این تحقیق بررسی کارایی فرآیند پراکسی الکتروکواگولاسیون در حذف COD آنتی‌بیوتیک آزیترومایسین از فاضلاب می‌باشد. مواد و روش‌ها: این مطالعه در راكتور در مقیاس آزمایشگاهی و روي نمونه‌های سنتتیک از آنتی‌بیوتیک آزیترومایسین انجام گرفت. در اين تحقيق تاثير پارامترهایی چون زمان واكنش، غلظت پراکسید هیدروژن، دانسیته جریان و pH بر راندمان حذف COD آنتی بیوتیک آزیترومایسین مورد بررسی قرار گرفت.  يافته‌ها: نتايج نشان دهنده تاثير غلظت اوليه آنتي بيوتيك، pH، دانسیته جريان، زمان واكنش و غلظت پراكسيد هيدروژن بر راندمان حذف بود. بیشترین راندمان حذف COD، 6/95 درصد، با غلظت 100 میلی گرم بر لیتر آنتی‌بیوتیک آزیترومایسین در زمان واكنش 60 دقیقه، دانسیته جریان 20 میلی آمپر بر سانتی متر مربع، pH برابر 3 و غلظت 5/1 میلی گرم بر لیتر پراکسید هیدروژن، به دست آمد. نتيجه گيري: روش پراكسي الكتروگواگولاسيون در حذف آنتي بيوتيك آزيترومايسين از فاضلاب كارآئي مناسبي دارد. گرچه از نظر اقتصادي بايد بررسي بيشتري در مقايسه با روش‌هاي ديگر صورت گيرد. &nbsp

بررسی کارآیی UV ،O3 و UV/O3 در راکتور با جریان قالبی جهت حذف اسید هیومیک از آب

ackground and Aims: Humic Acid (HA) is the most important combination of water humic materials. Removal of this compound leads to decreased production of chlorination by-products. This study set out with the aim of assessing the efficiency of O3, UV and UV/O3 in a plug-flow reactor in order to remove HA from water.Materials and Methods: The removal efficiency was assessed at three distinct steps through raw synthetic water samples containing specific concentrations of HA and treated water measurements of humic acid. Experiments were carried out in a laboratory scale plug-flow combined UV and ozonation system. The first question in this study sought to determine the compounded impact of ozone and UV on HA removal. The subsequent second and third questions in this research were to determine the separate effects of ozone andUV on the removal of target compound.Results: HA removal was slightly augmented in simultaneous presence of UV and ozone reaching 74.7% at initial HA concentration of 15 mg/L, pH 8, and reaction time of 25 min. However, on the question of separate effects of ozone and UV, this study found that the removal rate of HA, at similar situations, were 69% and 21%, respectively.Conclusion: Integrated application of UV and ozone outperformed conventional separate use of them in terms of HA removal. Higher removal efficiencies which achieved during ozone treatment, as compared with UV, might be due to higher oxidation power of ozone and OH radicals.زمينه و هدف: درمیان مواد هیومیکی موجود در آب، اسید هیومیک بعنوان مهمترین ترکیب پیش‌ساز تشکیل محصولات جانبی ناشی از کلرزنی مطرح است. حذف اسید هیومیک، کاهش تولید ترکیبات جانبی ناشی از کلرزنی آب را بدنبال دارد. این مطالعه با هدف بررسی کارآیی UV ،O3 و UV/O3 در راکتور با جریان قالبی جهت حذف اسید هیومیک از آب انجام گرفت. مواد و روش‌ها: این مطالعه در سه مرحله برروی نمونه‌های سنتتیک آب حاوی غلظت‌های مشخص از اسید هیومیک در یک سیستم تلفیقی UV و ازن‌زنی با جریان قالبی در مقیاس آزمایشگاهی انجام گردید. در مرحله اول مطالعه، تاثیر ازن و UV با هم و در مراحل دوم و سوم، تاثیر ازن و UV به طور جداگانه در حذف اسید هیومیک مورد بررسی قرار گرفت.    يافته‌ها: نتایج نشان داد با غلظت اولیه اسید هیومیک 15 میلی‌گرم در لیتر، pH برابر 8 ، غلظت ازن تزریقی 5/3 گرم در ساعت، زمان واکنش 25 دقیقه و با حضور UV و ازن، درصد حذف اسید هیومیک 7/74% بدست آمد. این در حالی است که در شرایط مشابه و با کاربرد ازن و UV به تنهایی، به ترتیب 69 و 21 درصد حذف اسید هیومیک حاصل شد.   نتيجه گيري: این مطالعه نشان داد که کاربرد ترکیبی UV/O3، کاراتر از بکارگیری ازن و UV به تنهایی می‌باشد. ازن راندمان بیشتری نسبت به UV در حذف اسید هیومک دارد که می‌تواند بخاطر قدرت اکسید کنندگی بالای ازن و رادیکال‌های OH باشد

Responses of activated sludge under a short-term exposure to facial scrub microbeads: implications from treatment performance and higher-life microbial population dynamics

In this study, four identical laboratory-scale sequencing batch reactors (SBRs) were continuously operated with different concentrations of microbeads (MBs) (5,000–15,000 MBs/L) to investigate the stress-responses of activated sludge under the MB exposure. It was found that the overall treatment performance (organic removal) of SBRs was fairly affected by short-term exposure to low levels of MBs; however, it was adversely affected as the concentration of MBs increased. The average concentration of mixed liquor suspended solids and heterotrophic bacteria in the reactor fed with 15,000 MBs/L were 16 and 30% less than in the pristine control reactor, respectively. Batch experiments further demonstrated that fairly low concentrations of MBs favored the development of dense microbial structures. Further increasing the MB concentrations to 15,000 MBs/L, however, distinctly weakened the settling performance of sludge. Morphological observations revealed suppressed uniformity, strength, and integrity of flocs reactors with the addition of MBs. Microbial community analyses revealed that the abundance of protozoan species declined 37.5, 58, and 64%, respectively, when SBRs were exposed to 5,000; 10,000; and 15,000 MBs/L as compared with the control reactor. The present work provided new insight into the possible effects of MBs on the performances and operational parameters of activated sludge. HIGHLIGHTS Plastic microbeads were extracted from facial scrubs and their characteristics were determined.; Responses of activated sludge upon exposure to microbeads (MBs) were elucidated.; The effect of MBs on operating indicators of the activated sludge process including sludge settleability bacterial and higher-life population were investigated.; The effect of MBs on treatment performance was studied.