岩土工程学报2025，Vol.47Issue(7)：1373-1381,9.DOI:10.11779/CJGE20231295
基于赤玉土强冻胀特性提高重金属污染黏性土淋洗效率研究
Improvement of washing efficiency of heavy metal-contaminated clayey soils based on strong frost-heave characteristics of Akadama soil
摘要
Abstract
The freeze-thaw synergistic chemical washing can remove heavy metal contaminants from clayey soils.However,the intake of eluent is low during the freezing process,resulting in low washing efficiency.Based on the idea of improving the frost heave of clayey soils and increasing water migration to improve the leaching efficiency,the freeze-thaw-leaching tests on soil columns are carried out by taking heavy metal-contaminated clayey soils as the research object and selecting strong frost-heave Akadama soil as the admixture.The results indicate that under the same freezing conditions,the frost-heave rate of Akadamas soil 124.48%,with the corresponding increase in the frost-heave amount and water intake of 5.85 times and 4.82 times that of clayey soils,respectively.This indicates an extremely strong frost-heave characteristic.The adsorption capacity of Akadama soil for Pb and Cd is weak,and it can be reused.After incorporating Akadama soil,the frost-heave amount and water intake of clayey soils significantly increase,with the maximum increments of 130.91%and 113.39%,respectively.After three freeze-thaw cycles,the removal rates of Pb and Cd reach 57.51%and 66.77%,respectively,representing an increase of 173.73%and 113.94%compared to those of the control group without Akadama soil.The SEM tests show that the structure of Akadama soil is severely broken and the number of pores increases,which is conducive to the migration and storage of water after freeze-thaw cycles.The method of using Akadama soil as an admixture soil to improve the freeze-thaw leaching efficiency has operability and universality in practical engineering applications.It provides a new approach for the remediation of heavy metal-contaminated clayey soils in seasonal frozen regions.关键词
赤玉土/冻融-淋洗/黏性土/重金属污染/土壤修复Key words
Akadama soil/freeze-thaw and washing/clayey soil/heavy metal contamination/soil remediation分类
土木建筑引用本文复制引用
芮大虎,王嘉义,张军,潘卫东,王淼..基于赤玉土强冻胀特性提高重金属污染黏性土淋洗效率研究[J].岩土工程学报,2025,47(7):1373-1381,9.基金项目
国家自然科学基金项目(42471155,42407269) （42471155,42407269）
冻土工程国家重点实验室项目(SKLFSE20191702) （SKLFSE20191702）
黑龙江省自然科学基金项目(LH2024D025)This work was supported by the National Natural Science Foundation of China(Grant Nos.42471155,42407269),Open Fund Project of State Key Laboratory of Frozen Soil Engineering and the Natural Science Foundation of Heilongjiang Province(Grant No.LH2024D025). （LH2024D025）
