RETRACTED: Removal of cadmium from mining soil using organic acid and ultrasonic waves (Retracted Article)

Ultrasonic techniques are applied to treat polluted soils because they are efficient, expeditious, inexpensive, and environmentally safe. In this study, the ultrasonic-assisted organic acid removal of cadmium from mining soil was investigated using the following setup: 0.1 mol/L citric and oxalic acid, a 1:20 solid-liquid ratio, and 30 min of ultrasonic-assisted time. A cadmium removal rate of 69.10% was obtained when using organic acids, while it was only 61.82% for removal by oscillation extraction. This implies that the ultrasonic-assisted removal method has beneficial effects on the removal of cadmium via organic acid. Speciation analysis of cadmium in mining soils before and after organic acid removal was performed using the Tessier sequential extraction procedure. The results showed that exchangeable species and those bound to manganese, iron and carbonates were lower after ultrasonic-assisted organic acid removal. This indicates that organic acids can remove most of the removable cadmium from soil in mining areas fast and efficiently.