ISSN:
1573-2932
Keywords:
mercury speciation
;
soil
;
thermal release analysis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
Notes:
Abstract Thermal release analysis of mercury species in contaminated soils was performed by temperature controlled continuous heating of the samples in a furnace coupled to an Atomic Absorption Spectrophotometer (AAS). It was shown that this method allows the identification of different redox states of Hg-species through their characteristic releasing temperature ranges. The method was applied to Hg-contaminated samples from an inactive chlor-alkali production plant in former East Germany (GER), and from a gold mining area in Poconé, Mato Grosso, Brazil (BRA), as well as synthetic soil samples obtained by spiking pre-heated soil matrices (GER and BRA) with the following mercury species: Hg0, Hg2Cl2, HgCl2, HgO and HgS. The samples GER, in general, frequently showed the presence of Hg2+ probably bound to humic substances, in the case of samples with higher total carbon content. Only in highly contaminated samples (〉3000 ppm of mercury) was Hg0 the predominant species. The samples BRA more frequently showed the presence of mercury species in the lower oxidation states, i.e. Hg1+ in combination with Hg0. The method allows observing changes in Hg-speciation in the samples with time, mainly changes among the oxidation states Hg0, Hg1+ and Hg2+. The treated GER matrix showed a stronger tendency to oxidise Hf-species than the BRA treated matrix, in which only added Hg0 is partially oxidised to Hg2+ and Hg1+. In contrast, the BRA matrix showed a pronounced tendency to reduce spiked Hg2+ to Hg1+. This may be the reason for the presence of Hg1+ in the majority of original BRA samples. The method appears to be very useful to study speciation of mercury and its dynamics. It can be used as a tool for monitoring mercury oxidation states and/or reactions of mercury in soils.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00171644
Permalink