Research Article 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 and Mohammed H. Essa 2 1 Department of Civil Engineering, ACHB, King Fahd University of Petroleum and Minerals, Hafar Al-Batin 31991, Saudi Arabia 2 Department of Environmental Engineering, University of Dammam, Dammam, Saudi Arabia 3 Environmental Engineering Department, University of Dammam, Dammam 31451, Saudi Arabia Correspondence should be addressed to Salihu Lukman; salihulukman@yahoo.com Received 16 March 2014; Accepted 27 May 2014; Published 24 July 2014 Academic Editor: Claudio Cameselle Copyright © 2014 Salihu Lukman et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Trivalent Cr is one of the heavy metals that are diicult to be removed from soil using electrokinetic study because of its geochemical properties. High bufering capacity soil is expected to reduce the mobility of the trivalent Cr and subsequently reduce the remedial eiciency thereby complicating the remediation process. In this study, geochemical modeling and migration of trivalent Cr in saline-sodic soil (high bufering capacity and alkaline) during integrated electrokinetics-adsorption remediation, called the Lasagna process, were investigated. he remedial eiciency 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 efects of voltage gradient, initial contaminant concentration, and polarity reversal rate on the soil pH, electroosmotic volume, soil electrical conductivity, current, and remedial eiciency of trivalent Cr in saline-sodic soil that was artiicially 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 eiciency is 64.75 %. 1. Introduction In early 1992, a discussion took place between the then Monsanto Chief Executive Oicer (CEO) and Administra- tor of the United States Environmental Protection Agency (USEPA) which ultimately led to the invention of the Lasagna process [1]. In the late 1993, Brodsky and Ho of Monsanto iled the irst Lasagna U.S. patent followed by a second one, all published in 1995 [2, 3]. In the Lasagna process, contaminated soil is remediated by creating at least one liquid permeable zone within a contaminated soil region and turning it into treatment zone. Appropriate materials (sorbents, catalytic agents, microbes, oxidants, and bufers) are then introduced into the treatment zone. An electrode is placed at the irst end of the contaminated soil region and another of opposite charge is placed at the opposite end of the contaminated soil region. A direct electric current is then transmitted through the contaminated soil region between the two electrodes. his causes movement of water and dissolved organic and inorganic materials in subsurface soils from one electrode (anode) to the other (cathode) under electroosmosis as a result of current movement from anode to cathode. In 1802 electroosmosis was irst observed; detailed study of the mechanism was done by Reuss [4] in his classic experiment reported by Abramson [5]. In 1909, Freundlich and Neumann [6] provided the general name “electrokinetic phenomena” to refer to the electrically driven mass low of dissolved contaminants and pore luid transport in soils induced by an applied DC voltage. It is made up of transport of pore luid via electroosmosis (EO) and transport of ions or charged species via electromigration [7]. he direction Hindawi Publishing Corporation e Scientific World Journal Volume 2014, Article ID 272794, 20 pages http://dx.doi.org/10.1155/2014/272794