CD-enabled elektrokinetic extraction of pollutants from soil

The electrokinetic extraction process removes metals and polar organic contaminants from low-permeability soil, mud, sludge, and marine dredging by applying electric current. This in situ technology based on electrochemical and electrokinetic processes is primarily a separation and removal technique for extracting contaminants from soils with an electric charge [1].

Applying direct current to the soil increases its temperature, which helps to desorb the organic contaminants and volatize the VOCs. Solubilizing agents (surfactants, CDs, cosolvents) can enhance the electromigration of the contaminants and enhance the removal efficiency [2-5]. Charged cyclodextrins such as CMBCD and glycine-BCD help the removal of both inorganic and organic pollutants [6-7]. The efficiency, however, depends on the soil properties (clay content, organic matter content, permeability, etc.) [8].

1. Gruiz, K., Meggyes, T. & Fenyvesi, E. (eds.) (2019) Engineering tools for environmental risk management. Volume 4. Risk Reduction Technologies and Case Studies. Boca Raton, Fl., CRC Press
2. Huang, D., Xu, Q., Cheng, J., Lu, X. & Zhang, H. (2012) Electrokinetic remediation and its combined technologies for removal of organic pollutants from contaminated soils. International Journal of Electrochemical Science, 7, 4528 -4544.
3. Ko, S.-O., Schlautman, M.A. & Carraway, E. (2000) Cyclodextrin-enhanced electrokinetic removal of phenanthrene from a model clay soil. Environmental Science & Technolology, 34(8), 1535-1541.
4. Yuan, S., Tian, M. & Lu, X. (2006) Electrokinetic movement of hexachlorobenzene in clayed soils enhanced by Tween 80 and beta-cyclodextrin. Journal of Hazardeous Materials, 137(2), 1218-1225.
5. Fu, R., Wen, D., Chen, X., Gu, Y., Xu, Z., Zhang, W. (2017) Treatment of decabromodiphenyl ether (BDE209) contaminated soil by solubilizer-enhanced electrokinetics coupled with ZVI-PRB. Environmental Science and Pollution Research 24(15), 13509-13518.
6. Jiradecha, C., Urgun-Demirtas, M, & Pagilla, K. (2006) Enhanced electrokinetic dissolution of naphthalene and 2,4-DNT from contaminated soils. Journal of Hazardous Materials, 136(1), 61-67.
7. Wang, G., Luo, J., Deng, N. (2013) Enhancement of electrokinetic removal of simazine and cadmium from co-contaminated soils by glycine-ß-cyclodextrin. Fresenius Environmental Bulletin 22(7), 1904-1912.
8. Khodadoust, A.P., Reddy, K.R., Narla, O. (2006) Cyclodextrin-enhanced electrokinetic remediation of soils contaminated with 2,4-dinitrotoluene. Journal of Environmental Engineering 132(9), 1043-1050.