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Electrocoagulation of Wastewater. Khalifa Jordan November 12, 2014. Overview. Introduction of Electrocoagulation Process Pros 2 Applications References. Concept of Electrocoagulation. Use of electric current to remove contaminants from water.
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Electrocoagulation of Wastewater Khalifa Jordan November 12, 2014
Overview Introduction of Electrocoagulation Process Pros 2 Applications References
Concept of Electrocoagulation • Use of electric current to remove contaminants from water. • The method is designed to remove heavy metals, organic materials, and inorganic contaminants. The contaminants also include oils, emulsified waste and bio hazardous materials. • The electrochemical process eliminates the usual steps of adding chemical additives that could further complicate the treatment process. • Typically the process separates the waste into three layers.
Process Variables Current Density pH Electrodes (Aluminum, Iron, Stainless Steel) Temperature Time Sample
Industrial Uses Petroleum Textile Dairy Mining Municipal Sewage
Benefits of Electrocoagulation The largest benefit of electrocoagulation is the environmental. The process limits the amount of waste and hazardous materials that are recirculated into ground and surface water. The stabilized waste and processed water can be repurposed within the operations of the industry. The process limits the amount of steps within the treatment process along with additives which increase operational efficiency while lowering cost. Process can handle a wide variety of waste and particle sizes which might otherwise cause issues (wear/tear) during other processes.
Electrocoagulation of Vegetable Oil RefineryWastewater using Aluminum Electrodes UmranTezcan Un a,*, A. SavasKoparal b, UlkerBakirOgutveren b
Basis of Study The electrocoagulation of vegetable oil refinery wastewater (VORW) in a batch reactor with aluminum electrodes. The operating parameters of the study were pH, current density, PAC (poly aluminum chloride) and Na2SO4 concentration. Determine an efficient method to process organic waste, oils and greases, sulphates, and phosphates due to vegetable oil processing.
Method/Application • The pH and current density were varied to determine optimal efficiency. • The amount of PAC(Coagulent aid) and supporting electrolyte (Na2SO4) were varied. • The amount of pollutant(COD) was analyzed using a spectrophotometer.
pH Analysis • Efficiencies of COD removal using aluminum plate electrodes by electrocoagulation were 77.3% for original pH of the wastewater (pH: 1.4), 96.5% for pH: 5, 98.9% for pH: 7 and 88.6% for pH: 9. The greatest pollutant removal which corresponded • to outlet COD concentration of 165 mg L1 was • achieved with the initial pH of 7 at the end of 120 min. Therefore, • further experiments were carried out at adjusted pH 7.
Current Density Analysis • The removal efficiency of COD was 94.5% at 35 mA cm2, 92.8% at 30 mA cm2 and 70.1% at 25 mA cm2 after 90 min reaction. At a high current density, the extent of anodic dissolution of aluminum increases, resulting in a greater amount of precipitate and removal of organics. (Song et al., in press)
PAC (Coagulent Aid) Analysis • The addition of PAC improved the removal efficiency from 94.5% at without PAC addition to • 97.6% at 0.25 g L1 PAC and to 98.9% (corresponded to 165 mg L1 COD) at 0.5 g L1 PAC at 90 min. • When the electrocoagulation was conducted with coagulant-aid, a higher removal of COD was achieved at shorter electrolysis time.
Na2SO4(Electrolyte) Analysis • Three supporting electrolyte concentrations were used in the experiments: 0.1, 0.3 and 0.5 M Na2SO4.
Conclusion • The results show that the removal efficiency of COD increased with the increasing applied current density and increasing PAC and Na2SO4 concentrations. • The most efficient removal capacity was achieved at the pH 7. • The results indicate that electrocoagulation is very efficient and able to achieve 98.9% COD removal in 90 min at 35 mA /cm2.
Assessment of Electrocoagulation for the Treatment of PetroleumRefinery Wastewater Muftah H. El-Naas*, Sulaiman Al-Zuhair, Amal Al-Lobaney, SouzanMakhlouf
Basis of Study Goal of the study was to evaluate the removal of sulfate and COD from petroleum refinery wastewater using electrocoagulation. Three types of electrodes were used for the study: aluminum, stainless steel, and iron. The variables of the experiments were current density, electrode arrangement, electrolysis time, initial pH, distance between the electrodes and temperature. The study also used two wastewater samples with varying levels contaminants. (WW-A and WW-B)
Method/Application • The reactor was set up with the desired variables. • Samples of the wastewater was taken and analyzed every 15min. • The samples were evaluated using a UV spectrophotometer. • The variables were manipulated throughout the experimental until they decided they reached optimal conditions.
Conclusions • The results indicated that when aluminum was used as both the anode and cathode the reduction of contaminants was the most effiecient and desired. both the contaminants. • The current density and compostion of the wastewater were determined to be major factors in the effieciency of the process. • The method was effective at a pH of 8 and 25C however thses two factors were deemed insignificant.
Bibliography Un, UmranTezcan, A. SavasKoparal, and UlkerBakirOgutveren. "Electrocoagulation of Vegetable Oil Refinery Wastewater Using Aluminum Electrodes." Journal of Environmental Management: 428-33. Print. El-Naas, Muftah H., Sulaiman Al-Zuhair, Amal Al-Lobaney, and SouzanMakhlouf. "Assessment of Electrocoagulation for the Treatment of Petroleum Refinery Wastewater." Journal of Environmental Management 91.1 (2009): 180-85. Web. "Leading Edge Goes Green with Hi-Tech Water Treatment Solution."Leading Edge Aviation Services. Ed. Admin. Leading Edge Aviation Services, 13 May 2010. Web. 12 Nov. 2014. Martin, Laura. "Electrocoagulation: A Shocking Approach To Wastewater Treatment." Water Online. N.p., 24 Jan. 2014. Web. 10 Nov. 2014. <, http://www.wateronline.com/doc/a-shocking-approach-to-wastewater-treatment-0001>. Demirci, S., Erdogan, B., Ozcimder, R., 1998. Wastewater treatment at the petroleum refinery, Kirikkale, Turkey, using some coagulants and Turkish clays as coagulant aids. Water Research 32, 3495–3499.