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
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