Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2014:2014:272794.
doi: 10.1155/2014/272794. Epub 2014 Jul 24.

Geochemical modeling of trivalent chromium migration in saline-sodic soil during Lasagna process: impact on soil physicochemical properties

Salihu Lukman  1 , Alaadin Bukhari  2 , Muhammad H Al-Malack  2 , Nuhu D Mu'azu  3 , Mohammed H Essa  2
Affiliations

Geochemical modeling of trivalent chromium migration in saline-sodic soil during Lasagna process: impact on soil physicochemical properties

Salihu Lukman et al. ScientificWorldJournal. 2014.

Abstract

Trivalent Cr is one of the heavy metals that are difficult to be removed from soil using electrokinetic study because of its geochemical properties. High buffering capacity soil is expected to reduce the mobility of the trivalent Cr and subsequently reduce the remedial efficiency thereby complicating the remediation process. In this study, geochemical modeling and migration of trivalent Cr in saline-sodic soil (high buffering capacity and alkaline) during integrated electrokinetics-adsorption remediation, called the Lasagna process, were investigated. The remedial efficiency of trivalent Cr in addition to the impacts of the Lasagna process on the physicochemical properties of the soil was studied. Box-Behnken design was used to study the interaction effects of voltage gradient, initial contaminant concentration, and polarity reversal rate on the soil pH, electroosmotic volume, soil electrical conductivity, current, and remedial efficiency of trivalent Cr in saline-sodic soil that was artificially spiked with Cr, Cu, Cd, Pb, Hg, phenol, and kerosene. Overall desirability of 0.715 was attained at the following optimal conditions: voltage gradient 0.36 V/cm; polarity reversal rate 17.63 hr; soil pH 10.0. Under these conditions, the expected trivalent Cr remedial efficiency is 64.75%.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Redox potential (Eh)-pH diagram for Cr–O–H system [12].
Figure 2
Figure 2
Coupled electrokinetics-adsorption experimental setup.
Figure 3
Figure 3
Weekly pH variation.
Figure 4
Figure 4
Weekly soil electrical conductivity variation.
Figure 5
Figure 5
Cumulative electroosmotic volume for each test.
Figure 6
Figure 6
Perturbation plots showing the relative significance of factors on soil pH (a) and electrical conductivity (c) (left). 3D response surface and contour plots showing how the influential factors affect soil pH (b) and electrical conductivity (d) (right).
Figure 7
Figure 7
pH profile with two GAC treatment zones for investigating bipolar effects (R11).
Figure 8
Figure 8
(a) Perturbation plot showing the relative significance of factors on electroosmotic volume. (b) 3D response surface and contour plots showing the influence of voltage gradient on cumulative electroosmotic volume.
Figure 9
Figure 9
Comparing variations of electric current with soil temperature: (a) current; (b) temperature.
Figure 10
Figure 10
(a) Perturbation plot showing the relative significance of factors on average electric current. (b) 3D response surface and contour plots showing the influence of voltage gradient on average electric current.
Figure 11
Figure 11
Trivalent Cr distribution and migration from the contaminated chamber to the GAC chambers after 13 tests.
Figure 12
Figure 12
Speciation diagram for trivalent Cr species at different weekly pH values.
Figure 13
Figure 13
Weekly percentage removal of trivalent Cr for 13 tests.
Figure 14
Figure 14
(a) Perturbation plot showing the relative significance of factors on trivalent Cr remedial efficiency. (b) 3D response surface and contour plots showing the influence of initial contaminant concentration on trivalent Cr remedial efficiency.
Figure 15
Figure 15
Combined and individual response desirability values for all responses and factors.
Figure 16
Figure 16
3D surface plot of the overall desirability variation relative to influential factors.
See this image and copyright information in PMC

References

    1. Ho SV, Hughes BM, Brodsky PH, Merz JS, Egley LP. Advancing the use of an innovative cleanup technology: case study of Lasagna. Remediation Journal. 1999;9:103–116.
    1. Brodsky PH, Ho SV. In situ remediation of contaminated soils. U.S. Patent 5.398.756, 1995.
    1. Ho SV, Brodsky PH. In-situ remediation of contaminated heterogeneous soils. U.S. Patent 5,476,992, 1995.
    1. Reuss FF. Sur un nouvel effet de l'électricité galvanique. Mémoires de la Societé Impériale des Naturalistes de Moscou. 1809;2:327–337.
    1. Abramson HA. Electrokinetic Phenomena and Their Application to Biology and Medicine. New York, NY, USA: Chemical Catalog; 1934. (ACS Monograph Series).

Publication types

LinkOut - more resources