@article{ART003331905},
author={SangYoon Min and Yoon-Young Chang},
title={Evaluation of Citric Acid Applicability for Unsaturated Lead-Contaminated Soil in Railway Sites},
journal={Journal of Environmental Impact Assessment},
issn={1225-7184},
year={2026},
volume={35},
number={2},
pages={79-89}
TY - JOUR
AU - SangYoon Min
AU - Yoon-Young Chang
TI - Evaluation of Citric Acid Applicability for Unsaturated Lead-Contaminated Soil in Railway Sites
JO - Journal of Environmental Impact Assessment
PY - 2026
VL - 35
IS - 2
PB - Korean Society Of Environmental Impact Assessment
SP - 79
EP - 89
SN - 1225-7184
AB - This study evaluated the remediation efficiency and field applicability of in-situ soil flushing using citric acid for Pb-contaminated soil in the unsaturated zone of a railway site through batch, column, and field-scale demonstrations. Batch tests compared organic acids (Citric and Oxalic acids) and an inorganic acid (HCl), showing a relatively high Pb reduction efficiency of 35.7% with 0.1 M citric acid. Although HCl exhibited a slightly higher reduction efficiency (37.9%) than citric acid, 0.1 M citric acid was selected as the optimal flushing agent considering cost-effectiveness, field applicability, and environmental friendliness. In the column test, residual Pb concentrations decreased with increasing pore volume (PV) of 0.1 M citric acid injection, and a reduction efficiency of 33.2~38.3% was achieved around 4~5 PV, meeting the Area 3 soil contamination concern criterion (700 mg/kg). Sequential extraction results indicated that Pb was predominantly associated with F4(Organic matter-bound) and F3(Fe/Mn oxide-bound) fractions before flushing, whereas after flushing the proportions of F4 and F3 decreased and those of F1(Exchangeable) and F2(Carbonate-bound) increased, suggesting mobilization and redistribution during the flushing process. In the field demonstration, 1 PV was estimated as approximately 15 ton based on the contaminated soil volume (36 m³) and effective porosity (0.416) reflecting site hydrogeological characteristics, and 0.1 M citric acid was injected at two-week intervals for a total of 6 PV (approximately 90 ton). As a result, the mean soil Pb concentration decreased from 1,050 ± 64.6 mg/kg to 670 ± 21.4 mg/kg, corresponding to an overall reduction of 36.2%, showing a removal trend comparable to that observed in the column test. These findings indicate that citric acid-based in-situ soil flushing has practical potential for Pb-contaminated railway soils under non-excavation conditions.
KW - Railroad site;Unsaturated zone;Lead contaminated soil;Citric acid;In-situ soil flushing
DO -
UR -
ER -
SangYoon Min and Yoon-Young Chang. (2026). Evaluation of Citric Acid Applicability for Unsaturated Lead-Contaminated Soil in Railway Sites. Journal of Environmental Impact Assessment, 35(2), 79-89.
SangYoon Min and Yoon-Young Chang. 2026, "Evaluation of Citric Acid Applicability for Unsaturated Lead-Contaminated Soil in Railway Sites", Journal of Environmental Impact Assessment, vol.35, no.2 pp.79-89.
SangYoon Min, Yoon-Young Chang "Evaluation of Citric Acid Applicability for Unsaturated Lead-Contaminated Soil in Railway Sites" Journal of Environmental Impact Assessment 35.2 pp.79-89 (2026) : 79.
SangYoon Min, Yoon-Young Chang. Evaluation of Citric Acid Applicability for Unsaturated Lead-Contaminated Soil in Railway Sites. 2026; 35(2), 79-89.
SangYoon Min and Yoon-Young Chang. "Evaluation of Citric Acid Applicability for Unsaturated Lead-Contaminated Soil in Railway Sites" Journal of Environmental Impact Assessment 35, no.2 (2026) : 79-89.
SangYoon Min; Yoon-Young Chang. Evaluation of Citric Acid Applicability for Unsaturated Lead-Contaminated Soil in Railway Sites. Journal of Environmental Impact Assessment, 35(2), 79-89.
SangYoon Min; Yoon-Young Chang. Evaluation of Citric Acid Applicability for Unsaturated Lead-Contaminated Soil in Railway Sites. Journal of Environmental Impact Assessment. 2026; 35(2) 79-89.
SangYoon Min, Yoon-Young Chang. Evaluation of Citric Acid Applicability for Unsaturated Lead-Contaminated Soil in Railway Sites. 2026; 35(2), 79-89.
SangYoon Min and Yoon-Young Chang. "Evaluation of Citric Acid Applicability for Unsaturated Lead-Contaminated Soil in Railway Sites" Journal of Environmental Impact Assessment 35, no.2 (2026) : 79-89.
