Non-Uniform Electrokinetic Removal of Heavy Metals from Contaminated Soil with Permeable Reactive Composite Electrodes

Abstract:

A hexagonal unit cell for non-uniform electrokinetic (EK) remediation was constructed and the electric field distribution of the cell was simulated using MATLAB software. The changes of soil pH and residues of heavy metals in different parts of the cell during the permeable reactive composite electrode electrokinetic (PRCE-EK) remediation were also studied. The results showed that, the changes of soil pH, the removal of heavy metals and the distribution of the non-uniform electric field in the cell were closely related to one another during the PRCE-EK remediation. Simulation of electric field distribution could help to predict the changes of soil pH of different parts of the cell, and then help to optimize the EK remediation process. The results also showed that an acidic migration band, which could prevent premature precipitation of heavy metals to a certain extent and promote EK removal of heavy metals, was formed in the whole hexagonal cell when the cathode used PRCE during the non-uniform EK remediation of cationic metallic ions, Cd²⁺ and Pb²⁺. After 480 hours of remediation, the total removal efficiency of Cd and Pb were 89.9% and 69.3%, respectively. Further prolonging remediation and constantly replacing electrodes with new ones could obtain better remediation results.

• Periodical: Applied Mechanics and Materials (Volumes 260-261)
• Pages: 1145-1150
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.260-261.1145
• Online since: December 2012
• Authors: Fang Liu
• Keywords: Electrode Configuration, Electrokinetic Remediation, Heavy Metal Contaminated Soil, Permeable Reactive Composite Electrode

References

[1] J. Virkutyte, M. Sillanpaa, P. Latostenmaa, Electrokinetic soil remediation-critical overview, Sci. Total Environ. 289 (2002) 97-121.

DOI: 10.1016/s0048-9697(01)01027-0

[2] Y.M. Luo, Current research and development in soil remediation technologies, Progess in Chem. 21 (2009) 558-565. (in Chinese).

[3] M.M. Page, C.L. Page, Electroremediation of contaminated soils, J. Environ. Eng. 128 (2002) 208-219.

DOI: 10.1061/(asce)0733-9372(2002)128:3(208)

[4] M. Pazos, M.A. Sanroman, C. Cameselle, Improvement in electrokinetic remediation of heavy metal spiked kaolin with the polarity exchange technique, Chemosphere 62 (2006) 817-822.

DOI: 10.1016/j.chemosphere.2005.04.071

[5] Y.Y. Wang, F.S. Meng, F. Chen, Effect of pH Control at the Cathode for the Electrokinetic Remediation Efficienc, Res. Environ. Sci., 20 (2007) 36-40. (in Chinese).

[6] T.Y. Li, S.H. Yan, L. Lin, et al. Study on the entanced electrokinetic remedy of a real sediment contaminated with hexachlorobenzene and heavy metals, Environ. Eng. 27 (2009) 105-109. (in Chinese).

[7] R.B. Fu, F. Liu, J. Ma, et al. Remediation of chromium(Ⅵ) contaminated soils using permeable reactive composite electrodes technology, Environ. Sci. 33 (2012) 280-285. (in Chinese).

[8] J. Ma, H.L. Luo, R.B. Fu, et al. Electrokinetic removal of heavy metals in contaminated soil using permeable reactive composite electrode, Environ. Pollut. Control 34 (2012) 17-23. (in Chinese).

[9] X.Y. Fan, Optimization and application of electrokinetic bioremediation technology, Tsinghua University, Beijing, 2006. (in Chinese).

[10] Q.S. Luo, Study of in situ bio-electrokinetic remediation of soil and its mechanism, Tsinghua University, Beijing, 2004. (in Chinese).

[11] Q.S. Luo, X.H. Zhang, H. Wang, et al. Influence of non-uniform electrokinetic remediation technology on soil properties, Tech. Equip. Environ. Pollut. Control 5 (2004) 40-45. (in Chinese).

[12] J.W. Ma, H. Wang, Q.S. Luo, et al. Mobilization characteristic and its mechanism of phenanthrene in soils by electrokinetics, China Environ. Sci. 27 (2007) 241-245. (in Chinese).

[13] Y. Sun, A.J. Gong, Y.H. Song, et al. Advance in modification method of zeolite, Inorg. Chem. Ind. 40 (2008) 1-4. (in Chinese).

[14] R.K. Lu, Analysis methods of soil agricultural chemistry, Chin. Agric. Sci. Tech. Press, Beijing, 2000. pp.228-235. (in Chinese).

[15] US EPA. Method 3052 Microwave assisted acid digestion of siliceous and organically based matrices. Washington DC: Environmental Protection Agency. (1996).

[16] F.C. Yu, C.K. Zheng, Electrodynamics, Peking University Press, Beijing, 1992. pp.63-69. (in Chinese).

[17] B.J. Alloway, Heavy metals in soil, Scotland: Blackie, Academic & Professional, 1995. pp.58-94.

[18] R.B. Fu, X.X. Liu, F. Liu, et al. Electrokinetic remediation of heavy metal contaminated soil using permeable reactive composite electrodes, Adv. Mater. Res. 518-523 (2012) 361-368.

DOI: 10.4028/www.scientific.net/amr.518-523.361