Sorption-desorption column tests to evaluate the attenuation layer using soil amended with a stabilising agent
Sorption-desorption column tests to evaluate the attenuation layer using soil amended with a stabilising agent
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DOI：
10.1016/j.sandf.2021.05.004
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发表时间：
2021-06
影响因子：
3.7
通讯作者：
T. Kato;Lincoln W. Gathuka;T. Okada;A. Takai;T. Katsumi;Y. Imoto;K. Morimoto;Miu Nishikata;T. Yasutaka
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文献类型：
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作者：
T. Kato;Lincoln W. Gathuka;T. Okada;A. Takai;T. Katsumi;Y. Imoto;K. Morimoto;Miu Nishikata;T. Yasutaka
采用丙烯酸树脂柱（105 cm × 10 cm）进行吸附-解吸柱试验，评价衰减层对地质污染物的吸附性能。衰减层材料是用1、5或10%的稳定剂改性的硅砂。该药剂的主要成分是氧化镁。材料的吸附行为由氟化物溶液（C 0 = 80 mg/L F-）确定，而解吸行为由蒸馏水确定。对于1、5和10%的稳定剂含量，分别在约1、20和50 PVF后发生断裂（C/C 0> 0.05）。一维对流-弥散方程模拟了从试验中获得的穿透曲线。这些预测给出了不切实际的估计，特别是对于C/C 0 = 0.05的突破点。对于1%的试剂含量，约20%的吸附质量，Ss，被解吸，但解吸质量的百分比，Sd，是更高的试剂含量小得多。吸附和解吸质量之间的差异被定义为固定分数，Ss-Sd。对于5%的药剂含量，Ss-Sd= 4.0 mg/g。结果表明，硅砂中加入氧化镁作为改性剂，可以有效地固定衰减层中的氟化物。
Sorption-desorption column tests using acrylic columns (ϕ5 cm ×h10 cm) were employed to evaluate the sorption performance of an attenuation layer against geogenic contamination. The attenuation layer material was silica sand amended with 1, 5, or 10% of a stabilising agent. The main component of the agent was magnesium oxide. The sorption behaviour of the materials was determined by a fluoride solution (C0= 80 mg/L F-), while the desorption behaviour was determined by distilled water. Breakthroughs (C/C0> 0.05) occurred after approximately 1, 20, and 50 PVF for stabilising agent contents of 1, 5, and 10%, respectively. The one-dimensional advection-dispersion equation modelled the breakthrough curves obtained from the tests. The predictions gave unrealistic estimates, especially for the breakthrough point whereC/C0= 0.05. For the 1% agent content, approximately 20% of the sorbed mass,Ss, was desorbed, but the percentage of desorbed mass,Sd, was much smaller for the higher agent contents. The difference between the sorbed and desorbed masses was defined as the immobilised fraction,Ss-Sd. For the 5% agent content,Ss-Sd= 4.0 mg/g. The results suggest that when silica sand is amended with magnesium oxide as an agent, the mixture can immobilise the fluoride in the attenuation layer.