بهسازی هدایت هیدرولیکی خاک بستر خاکچال‌ها با مواد طبیعی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانش آموخته کارشناسی ارشد، گروه مهندسی، دانشگاه پیام نور، تهران، ایران

2 دانشیار گروه مهندسی، دانشگاه پیام نور، تهران، ایران

3 استادیار پژوهش، موسسه تحقیقات خاک و آب، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران

4 استاد، گروه آبیاری و زهکشی، دانشکده کشاورزی، دانشگاه تربیت مدرس، تهران، ایران

چکیده

آلودگی خاک و سفره­های آب زیرزمینی بر اثر نفوذ شیرابه از محل دفن پسمانده­های شهری، از چالش­های مهم مدیریت منابع آب و خاک می­باشد. هدف از این پژوهش، ساخت آستری از مواد طبیعی موجود در محل دفن زباله بود که افزون بر نفوذپذیری مناسب، توانایی بیشتری در جذب آلاینده­ها نیز داشته باشد. دو ماده افزودنی طبیعی شامل بنتونیت و دی­کلسیم­فسفات، به ترتیب از صفر تا حداکثر 9 درصد و 2/0 درصد جرم خشک مواد پایه آستر به خاک درشت­دانه جمع­آوری شده از محل دفن شهر اوز در استان فارس، افزوده شد. آزمایش نفوذپذیری با آب و شیرابه مصنوعی انجام گرفت. نتایج نشان داد که برای مواد پایه حاوی 6 درصد بنتونیت، افزودن 2/0 درصد دی­کلسیم­فسفات باعث کاهش چشمگیرتر نفوذپذیری نسبت به بنتونیت به­تنهایی می­شود. به دلیل گرانروی بیشتر، نفوذپذیری شیرابه مصنوعی در مواد پایه آستر و همچنین حاوی 3 درصد بنتونیت، نسبت به آب کمتر بود. لیکن در 6 درصد بنتونیت، به دلیل خاصیت اسیدی، نفوذپذیری شیرابه بیشتر شد. شیرابه مصنوعی در 9 درصد بنتونیت تأثیر چندانی بر کاهش یا افزایش نفوذپذیری نداشت. علت این امر را می­توان افزایش چشمگیر ذرات ریزدانه رسی و درنتیجه افزایش خاصیت بافری خاک دانست.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Evaluating the improved hydraulic conductivity of double layer liners by bentonite and DCP

نویسندگان [English]

  • Masoud Gerashi 1
  • Amin Falamaki 2
  • Mahnaz Eskandari 3
  • Mehdi Homaee 4
1 Former M.Sc. Student, Department of Civil Engineering, Payame Noor University, Tehran, Iran
2 Associated Professor, Department of Engineering, Department of Civil Engineering, Payame Noor University, Tehran, Iran
3 Research Assistant Professor, Soil and Water Research Institute, Agricultural Research Education and Extension Organization (AREEO), Karaj, Iran
4 Professor, Department of Irrigation and Drainage, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
چکیده [English]

Soil and groundwater contamination due to leachate from municipal solid waste landfills is one of the most important environmental challenges for management of soil and water resources. This study was aimed to propose a landfill liner from the existing natural materials that in addition of having proper permeability, provides more capacity to absorb leachates. Two natural amendments including bentonite and DCP were applied to coarse landfill soil of Evaz city in Fars province between zero to a maximum 9% and 0.2% of base materials dry weight, respectively. The required permeability tests were conducted with both water and synthetic leachate. Results indicated that for the materials containing 6% bentonite, application of 0.2% DCP was considerably reduced the permeability compares to the bentonite application. Due to larger viscosity, the permeability of synthetic leachate in base liner materials and containing 3% bentonite, was less than the water. However, in the 6% bentonite application, due to its acidity, the permeability of leachate was increased. In 9% bentonite, synthetic leachate had minor effect in reducing or increasing the soil permeability. This can be attributed to significant increase of fine particles and the increase of soil buffering properties.

کلیدواژه‌ها [English]

  • Hydraulic conductivity
  • landfill liner
  • natural materials
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