Degradation of phenol with using of Fenton-like Processes from water

Phenol is one of the serious pollutants from the chemical and petrochemical industries. This pollutant due to its convoluted structure is resistant to biodegradation. One of the methods that are useful to remove this pollutant is advanced oxidation (AOP). A laboratory scale study was done on a synthetic wastewater containing phenol. All experiments were done in batch conditions and effect of variables pH, amount of hydrogen peroxide, iron dosage, contact time and an initial concentration on the phenol removal were tested. The remaining phenol concentration was evaluated using the DR-5000 device. In order to effect of these parameters, the experiment was performance at pH 2 to 6, 5 to 45 ml/ml of peroxide, and time of 5 to 60 minutes with 2 to 15 g/ml iron (Fe˚). The optimum pH, the ratio of hydrogen, Fe˚and time were 3, 15 ml, 8g and 5 minutes respectively. Chemical oxygen demand (COD) index was chosen as the parameter for evaluation in this study. Result showed that mineralization of phenol was not complete. The COD removal efficiency was obtained 71%. According to the results of this study, Fenton-like process can be used for conversion organic resistant compounds to other compounds with lower toxicity

The efficacy of O3, UV and UV/O3 on the removal of humic acids from water in a plug flow reactor

Background 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 thatthe 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.Key words: Advanced Oxidation, UV, Ozonation, Humic Aci

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

Removal of 1,2-dichloroethane from industrial wastewater with membrane filtration

Background and Aims: 1,2-dichloroetane [ethylene dichloride (EDC)] is a chlorinated hydrocarbon which is widely used to produce vinyl chloride. The later is the major precursor to PVC production. Wastewater originating from EDC production is characterized by high turbidity and contains ethylene dichloride and FeCl3 particles. The aim of the present study was to investigate the treatability of EDC effluent using membrane filtration.Materials and Methods: Laboratory scale experiments were carried out on Abadan petrochemical complex wastewater (EDC unit) with various membrane filtration processes that combine microfiltration with nanofiltration. Microfiltration membrane was used as a pretreatment to remove turbidity as well as FeCl3 fine particles, which may subsequently damage nanofiltration system. The microfiltration effluent was thereafter fed to a nanofiltration membrane cell. The filtration performance was assessed through turbidity, TDS, COD and 1,2-dichloroetane removals. pH, temperature and system pressure were also controlled during the study.Results: Successful removal of turbidity (97.5%) and FeCl3 particles (98%) was achieved by microfiltration. EDC concentration in raw effluent was ranged between 2,000 to 3,000 ppm. The nanofiltration membrane cell followed by microfiltration achieved a very high 1,2-dichloroetane removal (96.7) from water. The experimental results indeed showed that the permeate was consisted mainly of water, which asserts that 1,2-dichloroetane was separated in waste phase.Conclusion: The results obtained provide further support for previous researches into this brain area and support the application of membrane technology to remove and recovery of soluble organic compounds from petrochemical wastewater.Key words: Petrochemical wastewater, 1,2-dichloroetane, Membrane filtration, Nanofiltration, Microfiltratio

The efficiency of biological sludge on hexavalent chromium removal from aqueous solution

Background and aims: Out of different techniques for chromium (Cr) removal, biological treatment has a special status. This study was conducted to determine the efficacy of biological sludge on hexavalent Cr (VI) removal from aqueous solutions. Methods: In this experimental study, the required sludge was collected from municipal sewage refinery after aeration basin and introduced into the reactor and Cr and nutrients were added to it. The effect of dissolved oxygen (DO), Cr initial concentration, pH, temperature, glucose concentration, and contact time on chromium removal rate was evaluated. At each step, the samples withdrawn from the reactor were filtered and Cr (VI) level was measured using HACH Company instructions and spectrophotometry. Results: The findings of this study showed that at 2 mg/L DO, 80 mg/L Cr initial concentration, 5000 mg/L sludge concentration, pH= 3, 30°C temperature, 250 mg/L introduced glucose concentration, and 24 h contact time, about 97.5 % of Cr (VI) was removed. As DO, pH, and the introduced glucose concentration decreased and the initial sludge concentration increased, temperature and contact time of Cr removal efficiency increased. Conclusion: The results of this study showed that use of the activated sludge of sewage refinery could be used for Cr removal with regards to environmental aspects

Evaluation of the effectiveness of electro-coagulation-flotation process for removal toxicity of olive oil mill wastewater

Background: The olive oil mill wastewater is one of the contaminating food industrial wastewaters. Olive oil extraction process imports wastewater with high phenolic chemicals into the environment. In this study the toxicity of raw olive oil mill wastewater and the effluent of electro-coagulation have been investigated.Material & Methods: Germination test was used for evaluating the toxicity of wastewater and effluent process. Electro-coagulation-flotation examinations performed in a plexiglas electrochemical reactor with 1750 ml practical volume. 4 blades of aluminum and titanium as anode and cathode electrodes with a gap of 2 cm were connected to DC power supply in monopolar parallel mode.Results: Based on the information from this study, the pollution load of phenolic compounds in olive oil mill wastewater is 1000 times more than municipal wastewater. Also, the evaluation toxicity of effluent obtained from the process in natural pH of wastewater (pH=5.2), 117 mA/m2 current density and 30 minutes time process, suggests that the effluent causes plant species growth, even without dilution.Conclusion: The results obtained from this research can warn us to the risks of releasing these wastewaters without treatment and toxic effects on the different species of plants. Results demonstrated although using of electro-coagulation-flotation process removes high percent of pollutants of olive oil mill wastewater, but, it can’t attain the discharge limitations, then it should be more treated with some other methods.Key words: Toxicity, Electro-Coagulation-Flotation, Olive Wastewate

Removal of reactive dyes from textile wastewater using sonochemical process: effective parameters study

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Quality assessment of Tehran’s Firoozabad Channel surface runoff for irrigation uses

زمينه و اهدف: با توجه به اهميت آب و کمبود منابع آب در ايران، بهره‌برداري از روان آبهاي سطحي مي‌تواند جهت جبران بخشي از اين کمبود يک اقدم اساسي به حساب آيد. اين مطالعه با هدف بررسي کيفيت روان آب سطحي کانال فيروزآباد شهر تهران براي مصارف آبياري انجام گرفت. مواد و روش‌ها: اين تحقيق يک مطالعه تجربي-آزمايشگاهي بود. نمونه برداري در دو فصل بهار و تابستان سال 1394 از پايين دست روان آب سطحي کانال فيروزآباد در جنوب شهر تهران صورت گرفته است. جهت اخذ مجوزهاي لازم براي نمونه برداري و کسب اطلاعات ديگر هماهنگي با ارگان‌هاي ذيربط صورت گرفت. پارامترهاي BOD5، COD، TSS، pH، TP، TKN، هدايت الکتريکي،  بُر، کلرور، فلزات سنگين، کل کليفرم‌ها، کليفرم‌هاي موفوعي و نماتودهاي روده‌اي جهت تعيين کيفيت روان آب سطحي براي مصارف آبياري اندازه‌گيري شدند همچنين شاخص هاي SAR و %Na تعيين گرديد. نتايج با استانداردهاي آب کشاورزي مقايسه شد. يافته‌ها: نتايج نشان داد ميانگين BOD5، COD، pH و فلزات سنگين مورد اندازه گيري به جزء نيکل مطابق با استانداردهاي پساب براي آبياري توسط سازمان حفاظت محيط زيست ايران مي باشد. هدايت الکتريکي، کل جامدات محلول، SAR، کلرايد و بُر در محدوده کم تا متوسط و درصد سديم قابل قبول براي آبياري ارزيابي شد. ميانگين ميزان کدورت،TSS و همچنين تعداد باکتري هاي کليفرم و کليفرم مقاوم به حرارت بالاتر از استانداردهاي پسآب براي استفاده در آبياري و کشاورزي اندازه گيري شد. نتيجه‌گيري: گرچه بعضي از پارامترهاي اندازه گيري شده با استانداردها مطابقت دارد، ولي نتايج تحقيق نشان داد، در مورد برخي  از پارامترها نياز به تصفيه و بخصوص گندزدائي وجود دارد. همچنين در صورت استفاده، پايش مداوم اين روان آبها از نظر رعايت استانداردها براي آبياري ضروري مي‌باشد.  Background and Aims: Concerning the importance and limitations of water resources in particularly arid and semi-arid areas such as Iran, it seems that the use of surface runoff may be considered as a fundamental step to compensate a part of water scarcity. This study was aimed to assess the quality of surface runoff in Tehran’s Firoozabad Channel for irrigation uses.Materials and Methods: Throughout this experimental-laboratory study, sampling was done from the channel’s downstream in the south of Tehran during the spring and summer seasons in 2015. Arrangements were made well in advance with related organizations in order to sampling as well as to make use of required data. Water samples were analyzed for physic-chemical and biological parameters such as BOD5, COD, TSS, pH, SAR, Na%, TP, TKN, calcium, magnesium, sodium, electrical conductivity, boron, chloride, heavy metals, as well as intestinal nematodes, Total coliforms and Fecal coliforms.Results: The mean concentrations of BOD5, COD and heavy metals except for nickel as well as pH were in compliance with the standards set by Iranian Environmental Protection Agency for irrigation uses of effluents. Electrical conductivity, total dissolved solids, SAR, chloride, and boron were in the range of low to moderate. Furthermore, Na% was considered as permissible for irrigation uses. The average of turbidity, TSS and numbers of Coliforms and Thermotoerant Coliforms exceeded the desirable limits recommended for agricultural irrigation.Conclusion: The significance of results obtained simply emphasizes that although some measured parameters was found within national and international standards, there is a need for runoff treatment and notably disinfection for particular studied parameters. Additionally, continuous monitoring of such a surface runoff to determine its compliance with promulgated standards is recommended

Chemical Oxygen Demand Removal from Synthetic Wastewater Containing Non-beta Lactam Antibiotics Using Advanced Oxidation Processes: A Comparative Study

Background & Aims of the Study: Pharmaceuticals are considered as an emerging environmental problem due to their continuous discharge and persistence to the aquatic ecosystem even at low concentrations. The purpose of this research was the investigation of advanced oxidation processes (Fenton and Fenton-like) efficiency for the removal of nonbeta lactam Antibiotics of azithromycin and clarithromycin from synthetic wastewater. Materials & Methods: In this laboratory scale study, samples of synthetic wastewater were prepared from azithromycin and clarithromycin antibiotics. Concentration of samples was 200 mg/L. Chemical oxygen demand (COD) index was selected as the parameter for evaluation in this study. Fenton and Fenton-like oxidation processes were done on synthetic wastewater of azithromycin and clarithromycin. In Fenton (Fe2+/H2O2) and Fenton-like (Fe°/H2O2) processes the influence of pH, iron and hydrogen peroxide on the removal efficiency of the antibiotics were studied and the optimum values for each parameter were determined. Results: The optimum condition for Fenton in removal of azithromycin and clarithromycin were pH= 7 and 7, Fe2+ 0.45 mmol/L and 0.45 mmol/L, hydrogen peroxide 0.16 mmol/L and 0.2 mmol/L, and contact time of 1 h and 1 h, respectively. The optimum condition for Fenton-like in removal of clarithromycin and azithromycin were pH= 7 and 7, Fe0 0.3 mmol/L and 0.36 mmol/L, hydrogen peroxide 0.3 mmol/L and 0.38 mmol/L, contact time of 30 min and 30 min. Conclusions: The findings of this study demonstrate that the Fenton and Fenton-like processes under optimum conditions can play an important role in the removal of azithromycin and clarithromycin antibiotics from industrial wastewate

Investigation the Efficiency of Combined Coagulation and Advanced Oxidation by Fenton Process in the Removal of Clarithromycin Antibiotic COD

Antibiotics are considered among the major pollutants in water environments. In this study, removal of Claritromycine antibiotic has been studied from synthetic wastewater by combined coagulation and advanced oxidation processes. This study, was done in laboratory scale .  Samples of synthetic wastewater  were prepared from Claritromycin antibiotic. Concentration of samples were 200 mg/l. COD index was selected as a parameter evaluated in this study. In the first stage, coagulation process was done on synthetic wastewater and the proper condition was achieved (proper coagulant, optimum pH, dosage of coagulant). After that, Fenton oxidation process was done, on the effluent of coagulation process. In Fenton process the influence of pH, Fe2+ and hydrogen peroxide were studied on the removal efficiency of Claritromycin antibiotic and the optimum values for each parameter were determined. According to the results of this study, Poly Aluminum Chloride (PAC)  is the proper coagulant. With pH equal to 7 and 100 mg/l PAC, 84.37% removal of Claritromycine was achieved.  For fenton process, optimum parameters for the removal of Claritromycin were determined. The optimum condition for fenton process were, pH= 7, Fe2+ equal to 0.45 mmol/ l , hydrogen proxide equal to 0. 16 mmol/l, ratio of H2O2/Fe2+ equal to 0.4 and detention time of 1hour .With Applying of optimum conditions for combined coagulation and Fenton processes, 96.3% removal of Claritromycin was obtained