Japanese construction company Shimizu announced December 26 that it has completed the pilot project of purifying soil contaminated by the wartime defoliant Agent Orange at Bien Hoa Airport in suburban Ho Chi Minh, Vietnam. The company built the on-site soil washing plant and demonstrated that 95% of dioxin was removed.

The experiment was conducted as a part of the joint project by Vietnam and the US. The governments will decide if they apply Shimizu’s technology to the full-scale project which is scheduled to be launched in June 2020.

Starting the experiment in March, the company cleaned up multiple soil samples of different concentrations of dioxins gathered at the airport totaling 900 tons. The average rate of dioxin removal reached 95%. 70% of the purified soil can be reused.

Shimizu is conducting an additional experiment jointly with a US company to develop the method of detoxifying the whole quantity of soil. By heat-treating a residue of concentrated mud produced by the soil washing, they aim to convert the polluted soil to 100% reusable. The combination of the washing method and the heat treatment is expected to decontaminate the soil cost-effectively and environment-friendlily.
(2019/12/27)