Study of ultrasound-assisted sequential extraction procedure for potentially toxic element content of soils and sediments

For risk assessment of potentially toxic element (PTE) pollution of sediments and soils the fractionation by sequential extraction procedures are applied which require longtime leaching-shaking periods to achieve the dissolution equilibria. In this work an attempt is described for reduction the duration these leaching-shaking periods of the sequential extraction procedure proposed by Community Bureau of Reference (BCR) in 1993 by application of ultrasonic treatment. The fractionation of PTE content of BCR 701 certified reference sample was performed in three experiments: “A” experiment was the control, all extraction steps were performed with 16 hours shaking according to the BCR prescription; “B” experiment: in each extraction step was applied 1 hour preliminary ultrasonic treatment and after this 1 hour shaking; “C” experiment: only 1 hour ultrasonic treatment and no shaking was applied. It was experienced that by ultrasonic treatment can be efficiently increased the rate of dissolution when constant temperature of assisting medium was kept. 77% and 63% of element content extractable with the control “A” experiment can be extracted in “B” and “C” experiments, respectively. To achieve the 100% efficiency further experiments are in process.