Electrocoagulation Technology in Wastewater Treatment: A Review of Methods and Applications

The purpose of this paper is to review the relevant literature that published from 2010 to 2013 on topics related to electrocoagulation technology within the wastewater. The review describes and discussing issues surrounding electrocoagulation treatment within wastewater, including its concept, the background and various wastewater treatment techniques applications in the industry such as, optimization, modelling, combination composition and ,comparison with other treatment methods. Keywords: coagulation,electrochemical treatment , electrocoagulation, electrode, wastewater treatment

Combination of Electrocoagulation and Electro-Oxidation Processes of Textile Wastewaters Treatment

The present paper investigates the electrocoagulation-electrooxidation (EC-EO) process for the treatment of high-strength wastewater textile industry located in Babylon governance -Iraq. This EC-EO process evaluated the efficiency of electrocoagulation in treating contaminants.Textile wastewater such as BOD, COD, TDS, TSS, turbidity, nitrates, sulfate, total phosphates, electrical conductivity, oil and grease and the total phenols by using either Aluminum or (Iron) electrodes set in a bipolar structure or Titanium coated with iridium oxide Ti/IrO2 electrodes arranged in a monopolar outline in the same electrolytic cell. The first set of analyses that examined the best performance of textile wastewater was achieved by using Aluminum and Titanium coated with iridium oxide plates alternated in the electrode pack and operated at a current of 0.6 A during 90 min of treatment with pH adjusted to approximately 6.0. Further analysis showed that, 95% of oil and greases (O&G) were removed, however chemical oxygen demand (COD) and biological oxygen demand (BOD) removal reached 90% and 87%, respectively. Another important finding was that, more than 96 % of soluble phosphate was removed, and the process was effective in removing turbidity (98%) and suspended solids (98%). A total cost of treated textile effluent process under the best conditions involved using an EC - EO process including chemical electrode consumption, and energy was 2.03 USD/m3. Keywords: Electrocoagulation, Electro-oxidation, Titanium electrode, Textile wastewater, Aluminum electrode.

Air Pollution Levels by Re-suspended and Airborne Dust Due to Traffic Movement at the Main High Traffic Crossroads of Hilla City, Iraq

يتضمن هذا البحث عمليه مراقبه وتقييم لمستويات تلوث الهواء الناتج عن الغبار المتصاعد والمحمول بالهواء بسبب حركه المرور في تقاطعات الطرق الأكثر ازدحاما في مدينه ألحله وهي تقاطع نادر وتقاطع ألثوره. إن الغبار المتصاعد هو واحد من أكثر مصادر تلوث الهواء المساهم في التلوث الجوي الكلي وخصوصا عندما تكون الطرق غير مبلطه أو تحت الصيانة وبحمل مروري عالي مثل مايحصل ألان في تقاطع نادر الذي هو تقاطع رئيسي غير مبلط حاليا كونه تحت عمليه صيانة لأقامه مجسر عليه. تم إيجاد تراكير الدقائق العالقة الكلية للموقعين بواسطة جهاز اخذ العينات المحمول خلال ساعة الازدحام المروري وفي جو مشمس ومعتدل ولأربعه شهور( كانون الأول 2011, شباط 2012, نيسان 2012, أيار 2012 ). قد أكدت النتائج مساهمه الطرق غير ألمبلطه في تلوث الهواء. بينت النتائج أن معدل مستويات الدقائق العالقة في تقاطع نادر أعلى من معدلاتها في تقاطع ألثوره طوال فتره الدراسة حيث كان اقل مستوى للدقائق العالقة في تقاطع نادر(5676,67 مايكرو غرام\م3 ) هو أعلى من أعلى مستوى للدقائق العالقة في تقاطع ألثوره (4096,41 مايكرو غرام\م3 ). كما بينت النتائج أن تركيز الغبار المتصاعد ألمقاسه في هذه الدراسة (426.06-9348.95) مايكرو غرام\م3 هي أعلى بكثير من الحدود المسموحه في المواصفات ألقياسيه لوكالة حماية البيئة الامريكيه.This research includes a monitoring and an evaluation of the air pollution levels generated by the re-suspended and airborne dust due to traffic movement at the main busy crossroads of Hilla City, Nader Crossroad and Al-Thowra Crossroad, Iraq. The re-suspended dust is one of the most important contributors towards overall atmospheric pollution, especially when the roads are unpaved or under maintenance with high traffic load such as Nader Crossroad, which was under maintenance to construct a bridge on it. The concentrations of the total suspended particulate matters were determined at the two locations using portable air sampler during traffic rush hour on sunny moderated weekdays for four months, December 2011, February 2012, April 2012, and May 2012. The results have confirmed the contribution of the unpaved roads in air pollution. The results showed that the average TSP levels at Nader Crossroad was higher than the average TSP levels at Al-Thowra Crossroad during the total period of the study in which the minimum TSP level at Nader Crossroad was 5676.67 μg/m3, which was higher than the maximum TSP level at Al-Thowra Crossroad, 4096.41 μg/m3. In addition, the re-suspended dust concentrations that were measured in this study and ranged from 426.06 to 9348.95 μg/m3 are much higher than the American Environmental Protection Agency acceptable limits of national ambient air quality standards for the particulate matter. &nbsp

Characterization of Carbon nanotubes Near- Infrared Photoconductive Detector

Carbon nanotubes (MWCNTs,F-MWCNTs,SWCNTs) with different structure were fabricated into near-infrared photodetectors. Indium Tin Oxide (ITO) was used as a substrate to deposit CNTs by the drop casting method. The CNTs carrier concentrations, conductivity and carrier mobility were measured. Different types CNTs photodetectors exhibit a good photoconductive performance at a wavelength (980-1200nm) especially SWCNTs, responsivity was found to be (0.295 A W-1 ), specific detectivity (D*) 1—109 cm.Hz1/2 .W-1 and response time 0.049ns

Electrocoagulation using novel configurations electrodes for treatment of textile wastewater

Textile wastewater is considered as one of the most polluted wastewater. Conventional chemical coagulation is the most famous technique used to treat the textile effluent. However, this method produces low removal rate, long retention time and a large quantity of sludge and chemicals. The electrocoagulation (EC) technology is an active wastewater treatment used before sedimentation and filtration. It is still in the "black box" stage where process design, control, and optimization have been primarily empirical. In this research, the EC process was performed in two models for the treatment of textile wastewater. The first model is the conventional reactor with a new configuration that has static electrodes, classified in two phases. The two phases are the EC process alone, using Mp Al-Bp Al or Mp Al-Bp Fe and EC combined with electrooxidation process (EO) in the same reactor using MpTi-Bp Al or MpTi-Bp Fe. The second model is a novel reactor design with a rotating anode using aluminum electrodes. The rotating anode consists of 10 impellers supported by a shaft with 10 rings used as a cathode. The operational parameters were investigated, and the process was performed under optimal conditions. For model one, the results showed that the Mp Al-Bp Al was more effective than the Mp Al-Bp Fe and it was more efficient than chemical coagulation. The optimal combination (EC-EO) treatment was established with Mp Ti-Bp Al, and it is found to be more active than EC alone. The optimal parameters of the EC process with a novel rotating anode were 4 mA/cm2 current density, 150 rpm rotational speed, and 10 minutes reaction time. EC process with a rotating anode was more active than model one and chemical coagulation, where the removal efficiency was higher, and the operational cost were reduced significantly. The increase of impellers anode diameter led toenhance the mass transfer coefficient of ionic aluminum. This result was confirmed by computational fluid dynamic (CFD) simulation results. By solar cell supply, the EC process with rotating anode reactor using batch and continuous flow regime had almost similar removal rate. Zeta potential tests showed that reaction was chemo-adsorption, and this was validated by the X-ray diffraction (XRD) analysis. Moreover, the reaction product was environmental friendly. Hydrogen production was improved at a rotation speed of anode. The electrode passivation was reduced by increasing rotational speed of anode which led to an improved in the EC process performance and validated the reactor design. Finally, the contribution of this study is a novel EC reactor with a rotating anode which is more efficient and economic as compared to the conventional coagulation process in the textile wastewater treatment

Study the effect of metal cutting fluids in operating machines on operator health and the environment

Due to their function in reducing friction, reducing temperature in the cutting area and preventing corrosion, cutting fluids is an important part of many different materials operating processes. The main function of the liquid cutting is to control the temperature by cooling and lubrication, improving the workpiece quality by continuously removing the metal sculptor and the resulting limitation of the tool. Through this study, we will introduce method of automated coolant supply based on Arduino for CNC Machining, Coating the walls and ground of CNC workshop by making nano-coating to prevent the growth of harmful bacteria. In addition, we will give as well overviews and suggestions to address the risks related to the health of the operator that results from its exposure to inhaling the smell or fog generated from fluids and includes respiratory diseases (asthma, chronic bronchitis, and hypersensitivity pneumonia), cancer, skin diseases, and the eye in addition to environmental risks during disposal later as waste. In addition, some of the techniques used to overcome and reduce the risks of the cutting fluids used will be reviewed

Treatment of Textile Wastewater Using a Novel Electrocoagulation Reactor Design

This study explored the best operating conditions for a novel electrocoagulation (EC) reactor with the rotating anode for textile wastewater treatment. The influence of operating parameters like interelectrode distance (IED), current density (CD), temperature, pH, operating time (RT) and rotation speed on the removal efficiency of the contaminant was studied. A comparative study was done using conventional model with static electrodes in two phases under same textile wastewater. The findings revealed that the optimal conditions for textile wastewater treatment were attained at RT = 10 min, CD = 4 mA/cm2, rotation speed = 150 rpm, temperature = 25°C, IED = 1 cm and pH = 4.57. The removal efficiencies of color, biological oxygen demand (BOD), turbidity, chemical oxygen demand (COD) and total suspended solid (TSS) were 98.50, 95.55, 96, 98 and 97.10%, respectively, within the first 10 min of the reaction. The results of the experiment reveal that the newly designed reactor incorporated with cathode rings and rotated anode impellers provide a superior treatment efficiency within a short reaction time. The novel EC reactor with a rotating anode significantly enhanced textile wastewater treatment compared to the conventional model. The values of adsorption and passivation resistance validated the pollutants removal rate

Fabrication of Room Temperature NO2 Gas Sensor based on Silver Nanoparticles-Decorated Carbon Nanotubes

Functionalized-single wall carbon nanotubes (F-SWCNTs) were easily and efficiently decorated with Ag Nanoparticles. The sensor device consisted of a film of sensitive material (F-SWCNTs) and (F-SWCNTs/Ag NPs) deposited by drop coating on n-type porous silicon substrate. The two sensors show high sensitivity to NO2 gas at different temperatures. Test results demonstrated that the (F-SWCNTs/Ag NPs) have a better performance than (F-SWCNTs). The F-SWCNTs gas sensor shows high sensitivity (36 %) at RT with response time 11 sec, whereas F-SWCNTs/Ag NPs gas sensor shows better sensitivity (150.5 %) at RT with response time 8 sec. The device shows a very reproducible sensor performance, with high repeatability, full recovery and efficient response. The improvement in the detection of some specific gases (NO2) using Ag-functionalized nanotubes is explained