تصفیه شیرابه کهنه با روش انعقاد الکتریکی )مطالعه موردی: شیرابه زمین دفن کهریزک تهران)

نوع مقاله: مقاله پژوهشی

نویسندگان

1 استادیار گروه آلاینده‌های محیط زیست، پژوهشکده علوم محیطی، دانشگاه شهید بهشتی، تهران

2 کارشناس ارشد مهندسی شیمی، دانشکده مهندسی شیمی، واحد ماهشهر

چکیده

شیرابه زمین‌های دفن زباله شهری یکی از مشکلات مهم محیط زیستی است. امروزه روش انعقاد الکتریکی از جمله روشهایی است که برای تصفیه شیرابه مورد توجه است. در این فرایند، مواد منعقد کننده از انحلال الکترود فلزی تولید می‌شود. در این مقاله تصفیه‌پذیری شیرابه کهنه زمین دفن زباله کهریزک تهران به‌روش انعقاد الکتریکی با استفاده از الکترودهای فولادی گرید ST-12 ، ST-37 و CK-45 در مقیاس آزمایشگاهی با اندازه‌گیری پارامترهای COD ، ذرات معلق و تغییرات پتانسیل اکسایش و کاهش بررسی شد. میزان حذف COD با مقدار اولیه 160000 میلی‌گرم در لیتر در زمان 100 دقیقه و جریان 7/2 آمپر برای الکترودهای ST-12 ، ST-37 و CK-45 به‌ترتیب 66/42 ، 37/34 و 2/35 درصد به‌دست آمد. با افزایش زمان به 140 دقیقه میزان حذف COD به‌ترتیب 78/6 ، 38/4 و 12/12 درصد افزایش داشت. همچنین با افزایش دانسیته جریان اعمالی از 33/33 به 66/166 آمپر بر مترمربع افزایش حذف 98/38 ، 64/22 و 38/25 درصدی برای COD و 4/16، 79/19 و 71/18 درصدی برای ذرات معلق برای الکترودهای ST-12 ، ST-37 و  CK-45 به‌دست آمد. نتایج نشان داد الکترود ST-12 بهترین عملکرد را برای تصفیه شیرابه دارد به‌طوری که در دانسیته جریان 66/166 آمپر بر مترمربع معادل بارگذاری شارژ F/m3 46/155، 67/64 درصد از COD و 79/98 درصد از ذرات معلق حذف شدند.

کلیدواژه‌ها


عنوان مقاله [English]

Treatment of Old Leachate by Electro-Coagulation: A Case Study for Leachate of Kahrizak Landfill in Tehran

نویسندگان [English]

  • Seyed Hossein Hashemi 1
  • Amir Bagheri 2
چکیده [English]

Leachate of urban solid waste landfills is one of the most important of environmental concerns. Today, electro-coagulation is considered as a method for leachate treatment. In this process coagulants are produced during metallic electrode dissolution. In this article, treatability of old leachate of Kahrizak landfill of Tehran by electro-coagulation method was studied. The study was done in laboratory scale by using steel electrodes grades ST-12, ST-37, and CK-45 and measuring COD, SS and ORP parameters. COD removal was obtained 42.66, 34.37 and 35.2 percent for ST-12, ST-37 and CK-45 electrodes while the operation time and current were 100 min and 7.2 A for  initial COD concentration of 160,000 mg/l. COD removal increased 6.78, 4.38 and 12.12 percent when the operation time increased to 140 min, respectively. As well, COD removal was increased 38.98, 22.64 and 25.38 percent and SS removal was enhanced 16.4, 19.79 and 18.71 percent for ST-12, ST-37 and CK-45 electrodes, while the current density increased from 33.33 to 66.166 A/m2. The results also showed ST-12 electrode had the best efficiency for leachate treatment with COD and SS removal of 64.67% and 98.79% respectively while the current density was 66.166 A/m2 equals charge’s loading of 46.155 F/m3.

کلیدواژه‌ها [English]

  • leachate
  • Electrocoagulation
  • Current Density
  • Charge Loading
1- Nayak, S., Sunil, B.M., and Shrihari, S. (2007). “Hydraulic and compaction characteristics of leachate-contaminated lateritic soil.” J. of Engineering Geology, 94(3-4), 137-144.
2- Shokoh, A. (2007). “Laboratory study of reducing organic load of leachate by anaerobic process: Case study of Mashhad city.” M.Sc. Thesis, Amir Kabir University of Technology, Tehran. (In Persian)
3- Ilhan, F., Kurt, U., Apaydin, U., and Gonullu, M.T. (2008). “Treatment of leachate by electro coagulation using aluminum and iron electrodes.” J. of Hazardous Materials, 154 (1-3), 381-389.
4- Salem, Z., Hamouri, K., Djemaa, R., and Allia, K. (2008). “Evaluation of landfill leachate pollution and treatment.” J. of Desalination, 220(1-3), 108-114.
5- Di laconi, C., Ramadori, R., and Lopez, A. (2006). “Combined biological and chemical degradation for treating a mature municipal landfill leachate.” J. of Biochemical Engineering, 31(2), 118-124.
6- Deng, Y., and Englehardt, J.D. (2007). “Electrochemical oxidation for landfill leachate treatment.” J. of Waste Management, 27(3), 380-388.
7- Veli, S., O'ztu'rk, T., and Dimoglo, A. (2008). “Treatment of municipal solid wastes leachate by means of chemical and electro-coagulation.” J. of Separation and Purification Technology, 61(1), 82-88.
8- Holt, P.K., Barton, G.W., and Mitchell, C.A. (2005). “The future for electrocoagulation as a localized water treatment technology.” J. of Chemosphere, 59(3), 355-367.
9- Yousuf, M., Mollah, A., Schennach, R., Parga, J.R., and Cocke, D.L. (2001). “Electrocoagulation (EC)-science and applications.” J. of Hazardous Materials, 84(1), 29-41.
10- Dalvand, A., Gholami, M., Jonaydi, A., and Mahmoudi, N. (2009). “Study of electro-coagulation efficiency for removal of reactive red 198 dye from colored wastewater.” J. of Science and Technology of Color, (3), 97-105.
11- Jafarzadeh, N., and Daneshvar, N. (2006). “Treatment of textile wastewater contains basic dyes by electro-coagulation process.” J. of Water and Wastewater, 57, 22-29. (In Persian)
12- Asadi Habib, M. (2009). “Investigation of the removal of heavy metals from water and wastewater using electro-coagulation process (by emphasis on Cr6+).” M.Sc. Thesis, Amir Kabir University of Technology, Tehran. (In Persian)
13- Koshayian, S. (2006). “Electrical coagulation.” Roshd J. of Chemistry Education, 20(4), 29. (In Persian)
14- Dimoglo, A., Akbulut, H.Y., Cihan, F., and Karpuzcu, M. (2004). “Petrochemical wastewater treatment by means of clean electrochemical technologies.” J. of Clean Techn. Environ. Policy, 6(4), 288-295.
15- Emamjomeh, M.M., and Sivakumar, M. (2009). “Review of pollutants removed by electrocoagulation and electrocoagulation/flotation processes.” J. of Environmental Management, 90(5), 1663-1679.
16- Hanayei, A., and Ganjali Khosroshahi, M. (2009). “Treatment of arsenic in polluted water by electro-coagulation.” Iranian J. of Chemical Engineering, 7(37), 75-85.
17- Kobya, M., Demirbas, E., Dedeli, A., and Sensoy M.T. (2010). “Treatment of rinse water from zinc phosphate coating by batch and continuous electrocoagulation processes.” J. of Hazardous Materials, 173(1-3), 326-334.
18- Baeza, A., Fernandez, M., Herranz, M., Legarda, F., Miro, C., and Salas, A. (2004). “Removing uranium and radium from a natural water.” J. of Water, Air, and Soil Pollution, 173(1-4), 57-59.
19- Clescerl, L.S., Greenberg, A.E., and Eaton, A.D. (1999). Standard method for the examination of water and wastewater, 20th Ed., American Public Health Association, USA.
20- Wegst, C.W. (1999). Key to steel, Verlag Stahlschlussel, Germany.
21- Dena, W., and Huang, C. (2005). “Electrocoagulation for removal of silica nano particles from chemical-mechanical-planarization wastewater.” J. of Colloids and Surfaces A: Physicochem. Eng. Aspects, 254(1-3), 81-89.
22- Chen, X., Chen, G., and Yue, P.L. (2000). “Separation of pollutants from restaurant wastewater by electrocoagulation.” J. of Separation and Purification Technology, 19(1-2), 65-76.
23- Chen, G. (2004). “Electrochemical technologies in wastewater treatment.” J. of Separation and Purification Technology, 38(1), 11-41.
24- Yang, C.L. (2007). “Electrochemical coagulation for oily water demulsification.” J. of Separation and Purification Technology, 54(3), 388-395.
25- Mickley, M. (2004). Pretreatment capabilities and benefits of electrocoagulation, United States Office of Naval Research, Washington, D.C.
26- Kurt, U., Gonullu, M.T., Ilhan, F., and Varinca, K. (2008). “Treatment of domestic wastewater by electrocoagulation in a cell with Fe-Fe electrodes.” J. of Environmental Engineering Science, 25(2), 153-162.
27- Lee, P.C., Gau, S.H., and Song, C.C. (2007). “Particle removal of high-turbidity reservoir water by electro-aggregation.” J. of Environmental Engineering and Management, 17(5), 371-375.