This work aims to investigate the ability of using waste foundry sand (WFS) resulting as inexpensive by-product from steel industry in the low permeability barrier (LPB) and permeable reactive barrier (PRB) technologies for restriction of the movement of lead and nickel ions in the groundwater. Outputs of flask and tank tests certified that this material could capture these ions with sorption efficiency greater than 95% at time, pH, sorbent dosage, and speed equal to 60 min, 4 for lead and 6 for nickel, 2.5 g/100 mL, and 250 rpm, respectively. Sorption isotherm measurements were represented in a good manner by Langmuir model in comparison with Freundlich model with coefficient of determination (R2) greater than 0.99. So, the chemisorption was the predominant mechanism which could be supported by O-H, H-O-H, C-O, O-Si-O, and Si-O functional groups based on the Fourier transform infrared analysis. The maximum sorption capacity of WFS was 13.966 and 4.227 mg/g for lead and nickel ions, respectively, with corresponding affinities equal to 0.647 and 0.099 L/mg. Measurements signified that the hydraulic conductivity of WFS was 3.8 × 10−7 cm/s which satisfies the requirements of LPB. To obtain the acceptable values of permeability and reactivity, PRB was prepared from mixing 18% WFS with 82% filter sand. COMSOL software was able to simulate the measurements of two-dimensional tank packed with Iraqi soil aquifer in combination with WFS-LPB and WFS-filter sand PRB. Thicker barriers have a high ability in the protection of locations in the down-gradient side because their longevity increased dramatically with increase of barrier thickness.

中文翻译：

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废铸造砂作为渗透性和低渗透性屏障，限制地下水中铅和镍离子的传播

这项工作旨在研究在低渗透屏障 (LPB) 和渗透反应屏障 (PRB) 技术中使用废铸造砂 (WFS) 作为钢铁工业的廉价副产品来限制铅和镍离子移动的能力在地下水中。烧瓶和罐测试的输出证明，这种材料可以在时间、pH 值、吸附剂剂量和速度等于 60 分钟的条件下以大于 95% 的吸附效率捕获这些离子，铅为 4，镍为 6，2.5 g/100 mL，和 250 rpm，分别。与决定系数 (R2) 大于 0.99 的 Freundlich 模型相比，Langmuir 模型很好地表示了吸附等温线测量值。因此，化学吸附是主要的机理，可以得到 OH、HOH、CO、O-Si-O、和基于傅里叶变换红外分析的 Si-O 官能团。WFS 对铅和镍离子的最大吸附容量分别为 13.966 和 4.227 mg/g，相应的亲和力等于 0.647 和 0.099 L/mg。测量表明，WFS 的水力传导率为 3.8 × 10−7 cm/s，满足 LPB 的要求。为了获得可接受的渗透率和反应性值，将 18% WFS 与 82% 滤砂混合制备 PRB。COMSOL 软件能够结合 WFS-LPB 和 WFS-滤砂 PRB 模拟填充伊拉克土壤含水层的二维储罐的测量。较厚的屏障在保护下坡侧位置的能力很强，因为它们的寿命随着屏障厚度的增加而显着增加。