The Leachability of Mercury by Sequential Extraction

Abstrakt

From sequential speciation analysis of mercury in contaminated soils and reference materials, using extraction with KNO₃, KHF, Na₄P₂O₇, EDTA and HNO₃ solutions, follows that almost all Hg remained firmly bonded to soil and reference matrices. The analysis was then performed with soil samples enriched in Hg(NO₃)₂ (80 mg g^-1). The Hg distribution in soil samples was: exchangeable (carbonate) Hg < organic Hg < oxidic Hg; ca 34.5 % of the original Hg remained in soil matrix. The Hg distribution in the enriched reference material was: exchangeable (carbonate) Hg < organic Hg < oxidic Hg < sulfidic Hg. 70.25 % of the original Hg remained in the material.