Heavy metal removal capacity of individual components of permeable reactive concrete
Heavy metal removal capacity of individual components of permeable reactive concrete
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DOI：
10.1016/j.jconhyd.2016.12.005
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发表时间：
2017-01-01
影响因子：
3.6
通讯作者：
Kevern, John T.
中科院分区：
文献类型：
--
作者：
Holmes, Ryan R.;Hart, Megan L.;Kevern, John T.
可渗透反应屏障（PRB）是一种众所周知的地下水修复技术，使用工业化的反应介质，如零价铁和活性炭。渗透性活性混凝土（PRC）是一种由水泥和骨料等相对廉价的材料组成的替代反应介质。由于水泥水化过程中形成的复杂异质基质，多种多模式、同步过程驱动PRC系统内受污染地下水中金属的修复。研究了粗骨料、波特兰水泥、粉煤灰及其不同组合对溶液中铅、镉、锌去除效果的影响。金属的吸收、吸附、沉淀、共沉淀和内部扩散是在水合水泥基质中去除的常见机制，并且与骨料无关。局部聚集体可用作也具有高金属去除能力的可渗透结构，然而，聚集体的钙质来源是优选的，这是由于具有低可渗透性的改善的去除。单个吸附等温线呈线性或曲线上升，表明优选的去除过程。对于PRC样品，在测试的浓度范围内未达到金属饱和。结果，然后被用来比较去除活性炭和聚合物为基础的PRB估计材料成本的修复一个例子重金属污染的超级基金网站位于美国中西部，乔普林，密苏里州。(C)2016爱思唯尔B.V.保留所有权利。
Permeable reactive barriers (PRBs) are a well-known technique for groundwater remediation using industrialized reactive media such as zero-valent iron and activated carbon. Permeable reactive concrete (PRC) is an alternative reactive medium composed of relatively inexpensive materials such as cement and aggregate. A variety of multimodal, simultaneous processes drive remediation of metals from contaminated groundwater within PRC systems due to the complex heterogeneous matrix formed during cement hydration. This research investigated the influence coarse aggregate, portland cement, fly ash, and various combinations had on the removal of lead, cadmium, and zinc in solution. Absorption, adsorption, precipitation, co-precipitation, and internal diffusion of the metals are common mechanisms of removal in the hydrated cement matrix and independent of the aggregate. Local aggregates can be used as the permeable structure also possessing high metal removal capabilities, however calcareous sources of aggregate are preferred due to improved removal with low leachability. Individual adsorption isotherms were linear or curvilinear up, indicating a preferred removal process. For PRC samples, metal saturation was not reached over the range of concentrations tested. Results were then used to compare removal against activated carbon and aggregate-based PRBs by estimating material costs for the remediation of an example heavy metal contaminated Superfund site located in the Midwestern United States, Joplin, Missouri. (C) 2016 Elsevier B.V. All rights reserved.