Removal of Zinc by Nano-Scale Zero Valent Iron in Groundwater

Abstract:

Groundwater has long been identified as potential alternative of clean water supply due to its reliable quantity. However, pollution of groundwater due to anthropogenic factor still remains a challenging issue. To date, nanoscale zero valent iron (nZVI) has received great attention for its capability to treat various contaminants including chlorinated organics and metals. This study investigate Zinc (Zn) removal in aqueous solution by nanoscale zerovalent iron (nZVI). The characteristics study of the synthesized nZVI particles were investigated by its particle size and surface morphology using Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). SEM and TEM analyses verified that the particles size of synthesized nZVI were 71nm (< 100 nm). Structure of nZVI congragate to each other and a thin layer of oxide layer formed on the outer part of the nZVI particle. In the batch study, removal kinetic of Zn increased from 0.14 to 0.18 mins^-1 as the concentration of Zn increased from 0.1 to 0.5 ppm. However, the removal kinetic decreased from 0.162 to 0.148 mins^-1 as the amount of nZVI was increased from 0.25 mg/L to 2.50 mg/L. At pH 7, removal kinetic reached 0.157 mins^-1. However as the pH suspension decreases to pH 6.5, the removal kinetics decreased significantly to 0.144 mins^-1. The same behaviour was observed at pH 9 where the removal kinetics was decreased to 0.117 mins^-1. Removal kinetic of Zn significantly decreased at basic condition due to the formation of passivation layer which decreased the density of reactive surface area (e.g., Fe⁰ and Fe²⁺) on the surface of nZVI. Experimental results from this study can provide basic knowledge of effectiveness of Zn removal mechanisms by nZVI at different environment conditions and provide potential remediation technology for the treatment of toxic heavy metals in groundwater.

• Periodical: Applied Mechanics and Materials (Volumes 773-774)
• Pages: 1231-1236
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.773-774.1231
• Online since: July 2015
• Authors: Nik Nurul Ilani Nik Redzauddin*, Jalina Kassim, Amnorzahira Amir
• Keywords: Groundwater, NZVI, Removal Kinetic Rate, Zinc

References

[1] Y. Liang, X. Cao, L. Zhao & E. Arellano. (2014).

[2] T. Cheng, & H. E. Allen. (2006). Comparison of Zinc Complexation Properties of Dissolved Natural Organic Matter from Different Surface Waters, Journal of Environmental Management 80, pp.222-229.

DOI: 10.1016/j.jenvman.2005.09.007

[3] C.T. Walsh, H. H. Sandstead, A.S. Prasad, P. M. Newberne & P.J. Fraker. (1994). Zinc: health effects and research priorities for the 1990s. Environ Health Perspect. 102, p.5–46.

DOI: 10.1289/ehp.941025

[4] R. Singh, V. Misra, & R. P. Singh. (2012). Removal of hexavalent chromium from contaminated ground water using zero-valent iron nanoparticles. Environmental Monitoring Assessment, 184, 3643-3651.

DOI: 10.1007/s10661-011-2213-5

[5] H. Zhu, Y. Jia, & H. Wang. (2009). Removal of arsenic from water by supported nano zero-valent iron on activated carbon. Journal of Hazardous Material, 172, 1591-1596.

DOI: 10.1016/j.jhazmat.2009.08.031

[6] J. Dries, L. Bastiaens, D. Springael, S. N. Agathos, & L, Diels. (2005). Combined removal of chlorinated ethened and heavy metals by zerovalent iron in batch and continuous flow column system. Environmental Science & Technology, 39, 8460-8465.

DOI: 10.1021/es050251d

[7] R. Yuvakkumar, V. Elango, V. Rajendran & N. Kannan. (2011) Preparation and characterization of zero valent iron nanoparticle. Digest Journal of Nanomaterials and Biostructures, 6(4), 1771-1776.

[8] J. E. Martin, A. A. Herzing, W. Yan, X. Q. Li, B. E. Koel & C. J. Kiely. (2008). Determintation of the oxide layer thickness in core shell zero valent iron nanoparticles. Langmuir, 24, 4329-4334.

DOI: 10.1021/la703689k

[9] C. B. Wang & W. X. Zhang. (1997). Synthesizing Nanoscale Iron Particles for Rapid and Complete Dechlorination of TCE and PCBs, Environmental Science & Technology 31, No. 7.

DOI: 10.1021/es970039c

[10] N. Efecan. (2008). Characterization of The Adsorption Behaviour of Aqueous Cd(Ii) and Ni(Ii) Ions on Nanoparticles of Zero-Valent Iron, Izmir Institute of Technology.

[11] N. Khatoon, A. H. Khan, V. Pathak, N. Agnihotri & M. Rehman. (2013).

[12] W. Liang, C. Dai, X. Zhou, & Y. Zhang. (2014). Application of Zero-Valent Iron Nanoparticles for the Removal of Aqueous Zinc Ions under Various Experimental Conditions. PLoS ONE 9(1), e85686.

DOI: 10.1371/journal.pone.0085686

[13] N. Kržišnik, A. Mladenovič, A. A. Škapin, L. Škrlep, J. Ščančar & R. Milačič. (2014).

[14] U.S. Environmental Protection Agency, (2007). Nanotechnology White Paper, Science Policy Council.

[15] P. G. Tratnyek & R. L. Johnson. (2006). Nanotechnologies for environmental cleanup, Nanotoday.

[16] J. Fatisson, S. Ghoshal & N. Tufenkji. (2010). Deposition of Carboxymethylcellulose-Coated Zero-Valent. Langmuir 26(15), p.12832–12840.

DOI: 10.1021/la1006633