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NEW ZERO VALENT IRON (NZVI) FOR REMEDIATION OF
HEAVY METALS CONTAMINATED WATER
WAN ZUHAIRI WAN YAACOB , TENGKU NURADIBAH TENGKU KHALID, ABDUL
RAHIM SAMSUDIN & NORAZNIDA KAMARUSZAMAN
ACKNOWLEDGEMENT: The authors wish to thank Universiti Kebangsaan Malaysia for giving permission to attend this
conference. The authors would also thank Ministry of Higher Education (MOHE) for providing the research grant to undertake this
project (FRGS UKM-ST-07-FRGS0022-2010). Finally, the authors thank Mr. Muhammad Farid Adnan for technical assistance in the
Laboratory.
INTRODUCTION
Heavy metals are very toxic, highly persistent and non-degradable. They can contaminate
the environment (i.e. groundwater) and may pose very serious risk to health and our
ecosystems. This study was conducted to develop new zero valent iron (NZVI) using two
reduction processes :-
1) Reduction by heating a mixture of iron + carbon + lime
2) Chemical reduction using FeCl2.4H2O + NaBH4
There were two types of iron used in this study, i.e. iron ore from Jerantut and iron (a) (b) (c)
concretion in basaltic rock from Kuantan Pahang. Source of lime was from Bukit Figure 4. The amount of heavy metal (Pb) adsorbed by ZVI materials (a) ZV1 (b) ZVI2 (c) ZVI3
Panching in Kuantan and carbon from coconut shells.
Table 3. pH and EC values before and after the sorption tests on ZVI samples
Sample ID pH pH Electrical conductivity Electrical conductivity
Zero Valent iron (Before) (After) EC(µs), (Before) EC(µs), (After)
(ZVI)
ZVI 1 4 10.15 676 376
ZVI 2 4 10.87 676 328
ZVI 3 4 11.18 676 296
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Figure 1. Application of Zero Valent Iron (ZVI) for remediation of contaminated
groundwater
(a) (b) (c)
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Figure 5. Distribution Coefficient or sorption parameter (Kd) of ZVI at different temperatures. (a) 550oC; (b) 750oC and (c) 950oC
MATERIALS & METHODS
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1) Reduction by heating together iron + carbon + lime 2) Chemical reduction using FeCl2.4H2O + NaBH4
Table 1. The mixture percentage of iron, lime and carbon used in this study
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Sample ID Iron Concretion or Powdered Carbon
Iron Ore (%) Limestone (%) (%)
ZVI 1 95 2.5 2.5
ZVI 2 90 5 5
ZVI3 80 10 10
Figure 7. Scanning Electron Microscope (SEM) of nZVI
Figure 6. Particle size distribution of nZVI using
produced from chemical reduction showing platy texture.
Master-Sizer.
Figure 2a. A mixture of iron, Figure 2b. Zero Valent Iron
lime and carbon BEFORE produced AFTER heating
heating
2) Chemical reduction using FeCl2.4H2O + NaBH4
17.8 g FeCl2·4H2O + 50mL of 8.47 g of NaBH4 + 220mL of
absolute ethanol and distilled distilled water to produce ~1M
water solution (4:1, v/v) solution
The NaBH4 solution was added to the Fe2+ Figure 8. X-ray Photoelectron Spectroscopy (XPS) data of nZVI produced from chemical reduction.
solution (40–50 drops/min) while stirring The result indicates the zero valency of ZVI.
the reaction mixture well
CONCLUSIONS
Black particles of nZVI Figure 3. Nano Zero Valent Iron
(NZVI) after chemical reduction ZVI materials produced by heating reduction
RESULTS These materials have high Specific Surface Area (SSA) and Cation Exchange
Capacity (CEC). The SSA and CEC values increased with the increasing
1) Reduction by heating together iron + carbon + lime percentage of iron in the sample and increasing temperature used in this study
Table 2. Surface area and CEC values of ZVI 1, 2 and 3 after heating at 550, 750 (maximum 950oC). These materials also have high buffering capacity, capable
and 950oC to increase the pH values of contaminated water from 4 to 10. The adsorption
Sampel Temperature Surface Area Cation Exchange Capacity capacity for Pb is also very high and is largely controlled by the percentage of
ID (°C) (m2/g) CEC (meq/100 g) iron and the heating temperature used.
ZVI 1 550 °C 5.62 28.00
ZVI 2 550 °C 7.01 15.13
ZVI 3 550°C 29.07 34.53  ZVI materials produced by chemical reduction
ZVI 1 750 °C 8.06 28.39
The results of NZVI produced from chemical reduction such as color, particle
ZVI 2 750 °C 8.44 47.82 size, SEM image and XPS data indicate that nano Zero Valent Iron has been
ZVI 3 750 °C 34.43 53.43 successfully developed in this study. This platy micro-texture material has
ZVI 1 950 °C 10.54 60.28 nano size particles and contains zero valency iron. However, additional
ZVI 2 950 °C 23.90 156.75 chemical tests are still required to get the information on sorption capacity,
ZVI 3 950 °C 40.64 238.65 SSA and CEC values of this new material.
Address: Geology Programme, School of Environmental Sciences and Natural Resources, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia.
Tel: 603-89215390 Fax: 603-89215490 E-mail: yaacobzw@ukm.my website : www.ukm.my/zuhairi @ http://geo-environment.blogspot.com/
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