Co-management of landfill leachate concentrate with brick waste by solidification/stabilization treatment

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• 作者：Amjad Kallel ; Mohamed Ellouze ; Ismail Trabelsi
• 关键词：Solid waste (SW) ; Leachate concentrate ; Solidification/stabilization (S/S) ; Brick waste
• 刊名：Arabian Journal of Geosciences
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：10
• 期：4
• 全文大小：
• 刊物类别：Earth and Environmental Science
• 刊物主题：Earth Sciences, general;
• 出版者：Springer Berlin Heidelberg
• ISSN：1866-7538
• 卷排序：10

文摘

The treatment of landfill leachate by reverse osmosis (RO) generates huge volumes of heavily polluted concentrate that has to be properly treated before its discharge into the environment. The aim of this work was to assess the solidification/stabilization (S/S) treatment of the leachate concentrate (LC) for chemical/physical immobilization of contaminants and for obtaining durable monolithic matrix suitable for storage, landfilling, or use. In addition, the possible use of brick waste as a partial replacement of natural aggregates used for S/S process was investigated. Concrete mixtures were prepared using local PC, sand, gravel, and tap water/LC. The substitution of coarse aggregate material by brick waste was examined for the replacement ratios 25, 50, and 75%. Hardened concrete specimens were subject to compressive test as well as flexural strength test at 7 and 28 days. Besides, a leaching test was performed, and the collected eluates were analyzed for pH, total dissolved solids, chemical oxygen demand, chlorides, sulfates, phosphorus, and heavy metals. The aggregate replacement with brick waste showed various trends according to the substituted fraction size and ratio. A 28-day compressive strength of more than 25 MPa was obtained even at 50% simultaneous substitution of PC, gravel, and sand. Leaching test analysis confirmed that S/S could be a successful treatment for RO LC decreasing most of the pollutants to comply with landfilling criteria, except for chromium known to be mobile at high pH. Furthermore, the substitution of natural aggregates with brick waste revealed the possibility to cast valuable masonry units. However, a long-term assessment is still needed to ensure the mechanical and chemical stability/durability of concrete.