Chemical cleaning method
for a cadmium contaminated paddy field

Environmentally friendly, low cost soil cleaning technology

Features

This method cleans and uses existing soil, so there is no need to secure replacement uncontaminated soil. That eliminates the need for excavation of mountain soil and for transportation by dump trucks, and the resulting environmental impact.

This method does not use heavy machinery or dump trucks, and the soil level in fields remains unchanged after cleaning, so there is no need to overhaul irrigation channels, farming roads, etc. It extracts the cadmium from the soil, so its effects are long-lasting.　

This technique cleans the existing soil, so it can be reused and therefore has almost no impact on the nutrient levels of the soil. That prevents the soil from losing its fertility, making it possible to maintain rice harvest levels.

Cleaning process

Cleaning results

● The cadmium concentration in rice paddy soil was lowered by approximately 60% to 80%. (Figure 1)

● The cadmium concentration in harvested unmilled rice was lowered by approximately 70% to 90%, meeting the new standard (0.4mg/kg). (Figure 2)

● The harvest size after cleaning was not significantly different to that of pre-cleaning. (Figure 3)