Removal of oxyfluorfen from spiked soils using electrokinetic fences

Abstract

In this work, an accidental spill of Fluoxyl (commercial herbicide containing oxyfluorfen) is simulated in a pilot plant with a soil volume of 70x50x50 cm 3. The transport of Fluoxyl obtained by the free diffusion of pollution and under the application of the electrokinetic fences (EKF) technology are compared in a 34-day treatment. In addition, the temperature, conductivity, and pH are monitored daily. At the end of the experiment, a post-mortem analysis is carried out in order to obtain a 3-D distribution map of the pollutant. The results show that EKF is a good technology to remove oxyfluorfen from the soil without excavation because it is able to attain a fast transfer of oxyfluorfen to the flushing fluid used. After 34 days, the decrease in the concentration of oxyfluofen in the

Electro-bioremediation at the prototype scale: What it should be learned for the scale-up

“…The soil employed in this research is a low-plasticity clay (CL) according to the Unified Soil Classification System [23,24] and it comes from a zone with important agrarian activities near to Toledo (Spain). Its main characteristics can be found in previous works of our group [25][26][27][28][29][30][31][32][33]. and water pressure sensors (or "divers") were located at different positions into the soil.…”

“…In addition, the electric field exerted produces electrochemical processes, being the most important the electrolysis of water, which generates an acid and basic front caused by the oxidation and reduction of water on the anodic and cathodic surface, respectively. There are many strategies to remediate soil and they depend on the particular placement of electrodes and operation conditions, being the electrokinetic soil flushing and the electrokinetic soil fence two of the most important processes [11,12].…”

Calcite buffer effects in electrokinetic remediation of clopyralid-polluted soils

“…The numerical tool used was the M4EKR module, Multiphysics for EKR [26]. M4EKR is a numerical model developed by the authors as a result of the knowledge gained over the last years in the treatment of contaminated soils using electrokinetic techniques [27][28][29][30][31][32][33][34][35]. The M4EKR model has been implemented in COMSOL Multiphysics and is capable of simulating the general behaviour trends of an EKR process by solving a coupled problem of reactive transport and electric field.…”

Techno-economic analysis of the scale-up process of electrochemically-assisted soil remediation

“…These technologies are based on the application of an electric potential gradient (V/m) that produces a low electric current (A) between electrodes especially positioned in the soil, being the placement selected very important to get highly-efficient processes (Risco et al, 2016c;Risco et al, 2016e;Risco et al, 2016f). The electric field favours the movement of fluids, ions and charged particles by different transport phenomena, namely electroosmosis, electromigration and electrophoresis, respectively (Acar, 1993;Acar et al, 1995;Alshawabkeh et al, 1999;Reddy and Cameselle, 2009;Virkutyte et al, 2002).…”

“…The work presented in this manuscript aims to reduce this limitation, by discussing the technical aspects and the economic requirements of the scaleup of EASR, based on the experience acquired by the authors in the recent years, with the application of these technologies in different studies aimed to evaluate the remediation of soils polluted with PAH and pesticides. In those studies experimental setups of different scales that include lab, bench (Mena et al, 2016a;Mena et al, 2016b;Ramírez et al, 2015), pilot (Risco et al, 2016a;Risco et al, 2016b;Risco et al, 2015;Risco et al, 2016d;Risco et al, 2016e;Risco et al, 2016f) and prototype (López-Vizcaíno et al, 2016;López-Vizcaíno et al, 2017a, b) scales were used. This work presents not only an economic investment estimation of the assets but also an evaluation of the cost associated to all stages involved in start-up, operation and dismantling of EASR processes, giving also valuable information about the knowledge that can be obtained in each of them.…”