Environmental Research on Remediation of Cd-contaminated Soil by Electrokinetic Remediation

Yushan Wan, Juan Zhai, Anwei Wang, Hui Han, Meng Shen, Xin Wen

Ekoloji, 2019, Issue 107, Pages: 873-881, Article No: e107103

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Abstract

The basic idea proposed in this paper provides a novel and environmental friendly method to enhance the EK remediation of heavy metals contaminated soils. The remediation of Cd-contaminated soil is of great significance to the improvement of soil environment. As a new remediation technology, electrokinetic remediation has become a research hotspot in recent years. The test was carried out by self configuring Cd-contaminated soil to set up a hexagonal electrokinetic remediation device to study the effects of electric field strength, electrolyte types and bentonite addition on the removal rate of Cd in soils-contaminated by Cd, and further optimize the technical conditions of electrokinetic remediation. The results showed that the removal rate of total Cd was higher when the voltage intensity was 2v/cm, reaching 18.34%, so the electric field intensity was 2v/cm. Acetic acid was used as a circulating electrolyte to raise the current in the electrokinetic remediation process, which could effectively control the pH value of the cathode and reduce the concentration of Cd in the cathode. In the process of electrokinetic remediation, the addition of bentonite played a certain passivation role on all forms of Cd in soil. The highest removal rate of total Cd was 20.89%, and the energy consumption was reduced by 11.02%. Therefore, organic acids as electrolyte can not only effectively enhance the migration of Cd in soil, but also change the distribution of Cd in soil and improve the efficiency of remediation.

Keywords

electrokinetic remediation, Cd pollution, electrolyte, bentonite, environmental friendly method

References

  • Acar YB, Alshawabkeh AN (2000) Principle of electrokinetic remediation. Environmental Science & Technology, 27(13): 2638-2647.
  • Babel S, del Mundo Dacera D (2006) Heavy metal removal from contaminated sludge for land application: A review. Waste Management, 26: 988-1004.
  • Cang L, Zhou D (2011) Research status and trend of electrokinetic remediation technology for site environmental pollution. Environmental Monitoring Management and Technology, 23(3): 57-62.
  • Chen Y, Guo Y, Wei S (2004) Chelating agent and surfactant combined removal of Cd and Cr from municipal sludge. China Environmental Science, 24(1): 100-104.
  • Chu W, So WS (2010) Modeling the two stages of surfactant-aided soil washing. Water research, 35(3): 761-767.
  • Darmawan, Wada SI (2014) Effect of clay mineralogy on the feasibility of electrokinetic soil decontamination technology. Applied Clay Science, 20: 283-293.
  • Fan G, Zhu H, Hao X, et al. (2015) Effects of different reinforcing agents on electrokinetic remediation of soil contaminated by heavy metals. China Environmental Science, 35(5): 1458-1465.
  • Fan X, Wang H, Luo Q (2006) Optimal design of electrode matrix in electrokinetic bioremediation. China Environmental Science, 26(1): 34-38.
  • Hamed J, Acar YB, Gale RJ (2016) Pb(Ⅱ) removal from kaolinite by electrokinetics. Geotech. Eng, 117(2): 241-271.
  • Han Z, Wang Y, Guo J (2014) A review of heavy metal speciation in soil remediation. Environmental Science, 34(1): 271-278.
  • Harn BS, Popov BN, Zheng GH, et al. (2015) Mathematical modeling of hexavalent chromium decontamination from low surface charged soils. Journal of Hazardous Materials, 55: 93-107.
  • Li X (2015) Mechanism of electrokinetic remediation and removal of heavy metals from sludge and tailings. Changsha: Hunan University.
  • Li Z, Wang T, Huang H (2015) Study on remediation of Cd pollution in soil by chitosan modified bentonite. Chinese Journal of Soil Science, 47(2): 23-26.
  • Liu Y (2014) New electrodynamics technology and its application in remediation of heavy metal contaminated soils. Chongqing: Chongqing University.
  • Lu P, Feng Q (2009) Electrokinetic remediation of chromium contaminated soils by exchange electrode method. Journal of Environmental Engineering, 3(2): 354-358.
  • Luo Q, Wang H, Zhang X, et al. (2004) Advances in in-situ bioremediation enhanced by electrodynamics. Environmental Pollution & Control, 26(4): 268-271.
  • Peng G, Tian G (2010) Removal of heavy metals from electric sludge by enhanced electrokinetic remediation. China Environmental Science, 30(3): 349-356.
  • Peng L (2013) Experimental study on remediation of Cd-contaminated soil by electrokinetic method and its enhancement technology. Chengdu: Chengdu University of Technology.
  • Qian S, Jin W, Liu Z (2009) Electroremediation of Cu2+removal from soil. Journal of Chemical Engineering, 53(3): 236-240.
  • Qian S, Liu Z (2009) Introduction of remediation technology for-contaminated soil. Progress in Chemical Engineering, (4): 10-12, 20.
  • Wang X, Xu J, Yao H, et al. (2013) Effects of combined pollution of heavy copper, zinc, Cd and lead on soil microbial community. Journal of Environmental Sciences, 23(1): 22-27.
  • Wang Y, Meng F, Chen F (2007) Effect of cathode pH control on electrokinetic remediation efficiency of contaminated soil. Environmental Science Research, 20(2): 36-40.
  • Yuan H, Liu Y, Li X, et al. (2006) Study on removal of heavy metals from municipal sludge by electrokinetic remediation. China Water & Wastewater, 22(3): 101-104.
  • Zhang X, Zhu K, Li L (2008) Research progress and prospect of electrokinetic remediation of contaminated soil. Environmental Science and Management, 33(2): 64-68.
  • Zhou D, Cang L, Deng C (2014) Effects of complexing agent and acidity control on soil chromium electrokinetic processes. China Environmental Science, 25(1): 10-14.