EXTRACTION AND PRECONCENTRATION OF MERCURY(II) FROM AQUEOUS-SOLUTIONS

The extraction/preconcentration of mercury(II) from aqueous media using diphenyl-2-pyridylmethane (DPPM) in benzene has been studied. The factors influencing the extraction are optimized. An extractive preconcentration procedure has been proposed on the basis of its quantitative extraction in a single equilibration from 1 M hydrochloric acid solution containing 0.02 M potassium thiocyanate. Extracted mercury can be stripped almost completely into 10 M aqueous solutions of hydrochloric or perchloric acid. A mechanism has been proposed, and the extractable species is assumed to be HgCl2-n(SCN)„ (DPPM)2, where n — 1,2. Aqueous to organic volume ratios up to 100:1 can be used without loss of extraction efficiency, and the procedure can effectively be used in water pollution abatement studies. Copyright © 1979 by Marcel Dekker, Inc.