ScienceAsia 29 (2003): 291-296 |doi: 10.2306/scienceasia1513-1874.2003.29.291

Efficiency of Arsenic Removal From Soil
by Vetiveria zizanioides (Linn.) Nash
and Vetiveria nemoralis (Balansa) A. Camus

Thares Srisatit^1,*, Tuearnjai Kosakul² and Dusaluk Dhitivara³

ABSTRACT: Phytoremediation is an alternative technology to remove heavy metals in contaminated soil. Vetiveria zizanioides (Linn.) Nash (Surat Thani ecotype) and V. nemoralis (Balansa) A. Camus (Prachuabkirikhan ecotype) were used for arsenic removal experiments. Both plants were grown one month, then put in experimental pots, the soil of which contained sodium arsenate (Na₂HAsO₄.7H₂O) at different concentrations (control, 50, 75, 100, 125 and 150 mg As/kg soil). Three experiments were conducted for each concentration. Plants were harvested, observed for their growth, and analyzed for the arsenic accumulation in roots, stems and leaves after every 15 days up to 90 days. It was observed that all of the plants grew well in every concentration of arsenic, with 100% survival. V. zizanioides (Linn.) Nash had a higher number of plants per clump and diameters of clumps than V. nemoralis (Balansa) A. Camus. In contrast, the height and dry weight of V. nemoralis (Balansa) A. Camus were higher than those of V. zizanioides (Linn.) Nash. Accumulation of arsenic in the root of both species was higher than in the leaf. The amount of arsenic accumulation in V. zizanioides (Linn.) Nash was more than in V. nemoralis (Balansa) A. Camus. In addition, the arsenic removal efficiency of both species increased with increasing exposure time. The highest efficiency of V. zizanioides (Linn.) Nash was 0.05% after 90 days at an As concentration 75 mg As/kg soil dry weight, and the highest efficiency of V. nemoralis (Balansa) A. Camus was 0.04%, after 90 days at an As concentration of 125 mg As/kg soil dry weight.

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1 Department of Environmental Engineering, Faculty of Engineering,
2 Department of Botany, Faculty of Science,
3 Interdepartment of Environmental Science, Chulalongkorn University, Bangkok 10330, Thailand. Tel. (662) 218-6679 Fax. (662) 218-6666

* Corresponding author, Email: fentss@eng.chula.ac.th

Received 31 Oct 2002, Accepted 16 May 2003