Optimization of a High-Pressure Soil Washing System for Emergency Recovery of Heavy Metal-Contaminated Soil

Sang Hyeop Park, Agamemnon Koutsospyros and Deok Hyun Moon ()
Additional contact information
Sang Hyeop Park: Department of Environmental Engineering, Chosun University, Gwangju 61452, Republic of Korea
Agamemnon Koutsospyros: Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ 07030, USA
Deok Hyun Moon: Department of Environmental Engineering, Chosun University, Gwangju 61452, Republic of Korea

Agriculture, 2022, vol. 12, issue 12, 1-15

Abstract: Recent natural disasters, such as typhoons in South Korea and other countries around the globe, have resulted in loss of human life and damage to property, often causing contamination of nearby soil environments. This study focused on the emergency recovery of soil contaminated by heavy metals following a disaster such as typhoon flooding by applying a soil washing technique that used high-pressure water rather than chemical cleaning agents. Artificially contaminated soil containing 700 mg/kg Cu, 530 mg/kg Pb and 900 mg/kg Zn, was used. All three metals were present at levels higher than the Korean Warning Standards (500 mg/kg Cu, 400 mg/kg Pb, 600 mg/kg Zn) for region 2 (miscellaneous area). A high-pressure soil washing device was designed to treat 0.6 tons/h and optimal treatment was sought for varying levels of pressure (1, 3, 5 MPa), solid to liquid ratios (S/L) (1:1, 1:3, 1:5), and number of washing cycles (1, 2, 3). The high-pressure soil washing results showed that a 5 MPa washing pressure, 1:1 solid-liquid ratio, and one washing cycle were the optimum conditions to generate the highest heavy metal removal rates. Under optimal conditions, high-pressure soil washing attained removal efficiencies of Cu (37.7%), Pb (36.6%), and Zn (45.1%), and the residual concentrations of heavy metals in the remediated soil satisfied the Korean Warning Standard (Region 2). A comparison of the changes in particle size showed that after high-pressure washing, the mass fraction of coarse sand (CS, 2–0.42 mm) decreased by 23.3%, while that of fine sand (FS, 0.42–0.074 mm), silt, and clay (SC, <0.074 mm) increased by 4.2% and 19.1%, respectively. In addition, 31.1–34.6% of the CS heavy metal mass loading shifted to FS and SC fractions after washing. A comparative analysis of the soil surface morphology before and after washing using scanning electron microscopy (SEM) showed that the particles in the remediated soil became noticeably cleaner after high-pressure washing. This study demonstrated the feasibility of emergency recovery of heavy metal-contaminated soil using high-pressure washing without a chemical cleaning agent.

Keywords: high-pressure soil washing; physical soil washing; physical separation; heavy metal; emergency recovery (search for similar items in EconPapers)
JEL-codes: Q1 Q10 Q11 Q12 Q13 Q14 Q15 Q16 Q17 Q18 (search for similar items in EconPapers)
Date: 2022
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.mdpi.com/2077-0472/12/12/2054/pdf (application/pdf)
https://www.mdpi.com/2077-0472/12/12/2054/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jagris:v:12:y:2022:i:12:p:2054-:d:988718

Access Statistics for this article

Agriculture is currently edited by Ms. Leda Xuan

More articles in Agriculture from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().