Enhanced consolidation and removal of accumulated flocculants in dredged soil via leaching with vacuum preloading

• Published in: Environmental geochemistry and health Vol. 46; no. 8; p. 286
• Main Authors: Wang, Peng, Huang, Xianfeng, Li, Wenqian, Wang, Kairu, Chen, Zhanou, Liu, Hongzhi
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.08.2024; Springer Nature B.V
• Subjects: Accumulation; Chlorides - chemistry; Consolidation; Construction; Damage accumulation; Deionization; Drainage; Dredging; Earth and Environmental Science; Effectiveness; Environment; Environmental Chemistry; Environmental Health; Ferric chloride; Ferric Compounds - chemistry; Filtrate; Flocculants; Flocculation; Geochemistry; Leaching; Moisture content; Original Paper; Penetration resistance; Polymers; Public Health; Soil; Soil - chemistry; Soil environment; Soil Pollutants - chemistry; Soil resistance; Soil Science & Conservation; Soil stabilization; Soil water; Sustainable development; Terrestrial Pollution; Vacuum; Water; Water content; Removal; Flocculants; Consolidation; Leaching; Vacuum preloading
• ISSN: 0269-4042; 1573-2983; 1573-2983
• DOI: 10.1007/s10653-024-02067-3

The vacuum preloading coupling flocculation treatment is a widely employed method for reinforcing soils with high water content in practical construction. However, uneven distribution and accumulation of flocculants pose significant damage to the soil environment and result in uneven soil consolidation, leading to severe issues in subsequent soil development and exploitation. To address these concerns, an evolved leaching with vacuum method is developed for facilitating soil consolidation while preventing the accumulation of flocculant in the soil. In this study, five model tests are conducted in which FeCl 3 is chosen as the typical flocculant to promote soil consolidation, and deionized water is used for leaching. The final discharged water, settlement, water content and penetration resistance of soil are obtained to evaluate the soil reinforcement effect, while the flocculant removal effect is evaluated by the Fe 3+ content in the filtrate and soil. The comprehensive reinforcement and flocculant removal effect show that this method is extremely effective compared to traditional vacuum preloading. The two leaching is clarified as the best choice, resulting in a 22% decrease in the soil water content and a 25% in soil penetration resistance, meanwhile a 12.8% removal rate of the flocculant. The test results demonstrate that leaching with vacuum preloading can contribute to promoting soil consolidation and reducing the accumulation of flocculant in the soil, ensuring the safe and eco-friendly use of the soil for future applications. The conclusions obtained are of significant theoretical value and technical support for practical construction and sustainable development.