title: Evaluation of soil flushing of complex contaminated soil: an experimental and modeling simulation study.
abstract: The removal of heavy metals (Zn and Pb) and heavy petroleum oils (HPOs) from a soil with complex contamination was examined by soil flushing. Desorption and transport behaviors of the complex contaminants were assessed by batch and continuous flow reactor experiments and through modeling simulations. Flushing a one-dimensional flow column packed with complex contaminated soil sequentially with citric acid then a surfactant resulted in the removal of 85.6% of Zn, 62% of Pb, and 31.6% of HPO. The desorption distribution coefficients, KUbatch and KLbatch, converged to constant values as Ce increased. An equilibrium model (ADR) and nonequilibrium models (TSNE and TRNE) were used to predict the desorption and transport of complex contaminants. The nonequilibrium models demonstrated better fits with the experimental values obtained from the column test than the equilibrium model. The ranges of KUbatch and KLbatch were very close to those of KUfit and KLfit determined from model simulations. The parameters (R, β, ω, α, and f) determined from model simulations were useful for characterizing the transport of contaminants within the soil matrix. The results of this study provide useful information for the operational parameters of the flushing process for soils with complex contamination.
authors.affiliation: Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, South Korea.
authors.forename: Sung Mi
authors.initials: SM
authors.lastname: Yun
authors.affiliation: Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, South Korea.
authors.forename: Christina S
authors.initials: CS
authors.lastname: Kang
authors.affiliation: Department of Industrial Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, South Korea.
authors.forename: Jonghwa
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, South Korea. Electronic address: hankim@konkuk.ac.kr.
authors.forename: Han S
authors.initials: HS
authors.lastname: Kim
mesh_terms: D000327:Adsorption; D019343:Citric Acid / Q000737:chemistry; D052918:Environmental Restoration and Remediation; D007854:Lead / Q000737:chemistry*; D008962:Models, Theoretical; D009821:Oils / Q000737:chemistry*; D010578:Petroleum; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry; D015032:Zinc / Q000737:chemistry*
chemical_list: D009821:Oils; D010578:Petroleum; D012989:Soil Pollutants; D013501:Surface-Active Agents; D019343:Citric Acid; D007854:Lead; D012967:Sodium Dodecyl Sulfate; D015032:Zinc
keywords: Complex contamination; Desorption; Nonequilibrium model; Soil flushing; Transport