Extraction of arsenic in a synthetic arsenic-contaminated soil using phosphate

An environment-friendly and cost-effective extraction method has been studi ed for the removal of arsenic from contaminated soil. A yellow-brown forest soil was contaminated with arsenic(V) and used as a model soil. Among vari ous potassium and sodium salts, potassium phosphate was most effective in e xtracting arsenic, attaining more than 40% extraction in the pH range of 6- 8 with minimum damage to the soil properties. Exchange mechanism is propose d for the extraction of arsenic from soil by phosphate. Sequential extracti on shows that phosphate is effective in extracting arsenic of Al- and Fe-bo und forms. Arsenic of residual form was not extracted. Arsenic was efficien tly extracted by phosphate solution of pH 6.0 at 300 mM phosphate concentra tion and at 40 degreesC. (C) 2001 Elsevier Science Ltd. All rights reserved .