Potential application of Vetiver for remidiation of agent orange/dioxin contaminated soils at BienHoa Airbase

Project Manager: Dr.Ngo Thi Thuy Huong _ The VietNam Institute of Geosciences and Mineral Resources (VIGMR)

The results shows that Vetiver – Monto ecotype could grow well and normally on soil polluted by Dioxin and Dioxin-Like Compounds in light and medium levels. The growth monitoring data indicated that the best growth period of Vetiver was eight months after planted when the stems reached up to 2.5 m, over 30 new tillers arose from mother plants and its flowers were in full bloom. Vetiver after that entered the decline phase; considered as the normal biological cycle of this grass in other normal soil environments.
In addition, Vetiver could absorb dioxin: 2,4 D; 2,4,5 T and As into its huge roots, then moving to shoots. Absorption levels are dependent on many natural factors such as growth cycles, care conditions, climates, and weather, etc. Dioxin absorbed into the root system dissolved or converted into less toxic substances; for example, toxic chemicals such as 2,4 D; 2,4,5 T, As and especially dioxin decreased over time. Specifically, plots with DECOM1 reduced 38% of dioxin (equivalent to about 702 pg TEQ), while plots without DECOM1 reduced 24% (equivalent to about 735 pg TEQ) after one year of planting.
Experts were very impressive by such those positive results and expected the project with more further research would make certain impacts because dioxin is not only the herbicides stagnated from previous wars but landfills, cement and steels plants also has high levels of dioxin. It is necessary to keep studying on the mechanism of Vetiver in transforming from high toxic into less toxic or non-toxic substances. In addition, what to do with Vetiver removed from contaminated soil should also be figured out.
On August 8, 2017, at the Vietnam Research Community Forum hosted by USAID, US Ambassador _ Mr.Ted Osius announced to give the cooperative research grant under the Partnerships for Enhanced Engagement in Research (PEER) Program to further investigates on (1) How Vetiver treats dioxin contaminated soil, (2) What are the roles of Vetiver, and (3) What are the roles of organism in the root system in the process of treating dioxin? The project is expected to be run for three years from January 2018 to December 2020.