Soil heterogeneity effects on acid flushing of lead-contaminated soil
Nakagawa, Kei ; Wada, Shin-Ichiro ; Momii, Kazuro Momii and Berndtsson, Ronny LU
(2008)
In Environmental Modeling and Assessment
13.
p.121-134
- Abstract
- A compact model for evaluation of acid flushing of heavy-metal-contaminated soil in a small-scale on-site treatment plant is proposed. The model assumes that the soil was re-packed in a container after excavation resulting in a soil structure with heterogeneous and random physical and chemical properties. To evaluate the effects of heterogeneity on the efficiency of contaminant removal by acid flushing, a numerical analysis of lead transport in the heterogeneous soil medium was performed. The model examines cation exchange and surface complexation reactions involving three cations (Ca, Pb, and H) and one anion (Cl) in both dissolved and exchangeable forms, two Pb surface complexes (SOPbCl and SOPbOH), and one Cl surface complex (SOH2Cl).... (More)
- A compact model for evaluation of acid flushing of heavy-metal-contaminated soil in a small-scale on-site treatment plant is proposed. The model assumes that the soil was re-packed in a container after excavation resulting in a soil structure with heterogeneous and random physical and chemical properties. To evaluate the effects of heterogeneity on the efficiency of contaminant removal by acid flushing, a numerical analysis of lead transport in the heterogeneous soil medium was performed. The model examines cation exchange and surface complexation reactions involving three cations (Ca, Pb, and H) and one anion (Cl) in both dissolved and exchangeable forms, two Pb surface complexes (SOPbCl and SOPbOH), and one Cl surface complex (SOH2Cl). The transport of these species during flushing with acid in a synthetically generated two-dimensional heterogeneous soil was simulated in the model. Results indicated that the flushing fluid preferentially followed pathways with large permeability. The heterogeneous cation exchange capacity (CEC) distribution and surface complexation sites had a significant effect on the transport of dissolved species. Because the CEC was set to a relatively low value, Pb was adsorbed mainly as surface complexes (SOPbCl and SOPbOH). Simulation results suggest that blocks of low hydraulic conductivity located in the upper part of the model domain greatly impede solute transport. Ponding conditions did not significantly affect the efficiency of decontamination. The model and its results are useful in the design of small-scale treatment plants for acid flushing. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/587390
- author
- Nakagawa, Kei
; Wada, Shin-Ichiro
; Momii, Kazuro Momii
and Berndtsson, Ronny
LU
- organization
- publishing date
- 2008
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- numerical simulation, lead-contaminated soil, acid flushing, cation exchange, surface complexation
- in
- Environmental Modeling and Assessment
- volume
- 13
- pages
- 121 - 134
- publisher
- Springer
- external identifiers
-
- wos:000252418500009
- scopus:38349095880
- ISSN
- 1573-2967
- DOI
- 10.1007/s10666-006-9076-0
- language
- English
- LU publication?
- yes
- id
- 6d176622-91bc-40fd-8d3d-fd412c681fcd (old id 587390)
- date added to LUP
- 2016-04-01 11:42:30
- date last changed
- 2022-04-20 20:35:59
@article{6d176622-91bc-40fd-8d3d-fd412c681fcd,
abstract = {{A compact model for evaluation of acid flushing of heavy-metal-contaminated soil in a small-scale on-site treatment plant is proposed. The model assumes that the soil was re-packed in a container after excavation resulting in a soil structure with heterogeneous and random physical and chemical properties. To evaluate the effects of heterogeneity on the efficiency of contaminant removal by acid flushing, a numerical analysis of lead transport in the heterogeneous soil medium was performed. The model examines cation exchange and surface complexation reactions involving three cations (Ca, Pb, and H) and one anion (Cl) in both dissolved and exchangeable forms, two Pb surface complexes (SOPbCl and SOPbOH), and one Cl surface complex (SOH2Cl). The transport of these species during flushing with acid in a synthetically generated two-dimensional heterogeneous soil was simulated in the model. Results indicated that the flushing fluid preferentially followed pathways with large permeability. The heterogeneous cation exchange capacity (CEC) distribution and surface complexation sites had a significant effect on the transport of dissolved species. Because the CEC was set to a relatively low value, Pb was adsorbed mainly as surface complexes (SOPbCl and SOPbOH). Simulation results suggest that blocks of low hydraulic conductivity located in the upper part of the model domain greatly impede solute transport. Ponding conditions did not significantly affect the efficiency of decontamination. The model and its results are useful in the design of small-scale treatment plants for acid flushing.}},
author = {{Nakagawa, Kei and Wada, Shin-Ichiro and Momii, Kazuro Momii and Berndtsson, Ronny}},
issn = {{1573-2967}},
keywords = {{numerical simulation; lead-contaminated soil; acid flushing; cation exchange; surface complexation}},
language = {{eng}},
pages = {{121--134}},
publisher = {{Springer}},
series = {{Environmental Modeling and Assessment}},
title = {{Soil heterogeneity effects on acid flushing of lead-contaminated soil}},
url = {{http://dx.doi.org/10.1007/s10666-006-9076-0}},
doi = {{10.1007/s10666-006-9076-0}},
volume = {{13}},
year = {{2008}},
}