Work

Enhanced diesel removal from contaminated soil: A coupled approach of negative-pressure extraction and subzero-temperature-induced migration

Year: 2026

Type: article

Abstract: To reduce the energy demand of conventional high-temperature thermal desorption and related technologies for remediating organic-contaminated soils, and to elucidate the evolution of liquid-phase contaminants in soils subjected to coupled temperature–pressure fields, this study develops a remediation process that couples negative-pressure extraction with subzero-temperature-induced migration of diesel in porous media. The method exploits the depression of liquid boiling points under reduced pressure and the acceleration of fluid transport driven by temperature gradients in porous media. Saturated diesel-contaminated soils with different initial dry densities ( ρ d ) were treated under low-temperature negative-pressure conditions, and diesel removal tests were conducted. The results show that, for all ρ d considered, the removal efficiency exhibits a characteristic three-stage temporal evolution. Under subzero temperature and negative pressure, the residual diesel mass fraction in the samples stabilizes at approximately 10–12%, approaching the residual liquid content of the soil and indicating that late-stage removal is controlled by high-boiling fractions and strong sorption. Post-test energy-dispersive X-ray spectroscopy further confirms that the carbon content in the soil decreases from about 35% to 13%, demonstrating a substantial reduction in organic contamination. Overall, the proposed approach achieves stepwise, high-efficiency removal of high-boiling organic pollutants at moderate to low energy input, and provides quantitative criteria for the scale-up design and energy optimization of subzero negative-pressure remediation processes.

Source: SOILS AND FOUNDATIONS

DOI: 10.1016/j.sandf.2026.101742

Authors: Liyu Yi, Jielong Rao, Yong Wan, Yaoqiang Chen, Zhixiang Chen

Institutions: Chinese Academy of Sciences, Institute of Rock and Soil Mechanics, State Key Laboratory of Geomechanics and Geotechnical Engineering, Shenyang Jianzhu University

Language: English

Topic: Groundwater flow and contamination studies

Subfield: Environmental Engineering

Field: Environmental Science

Domain: Physical Sciences

SDGs: Responsible consumption and production, Life on land, Climate action

Open Access status: gold

Estimated APC paid: $1,200