Mercury and Tin Speciation in the Environment of Gold Tailings Dumps in the Central Rand, Johannesburg

Authors: Cukrowska, EM; Lusilao-Makiese, J; Nsengimana, H; Tutu, H; Amouroux, D; Tessier, E Paper is not available for download Contact Us

DOI https://doi.org/10.36487/ACG_repo/852_62

Cite As:
Cukrowska, EM, Lusilao-Makiese, J, Nsengimana, H, Tutu, H, Amouroux, D & Tessier, E 2008, 'Mercury and Tin Speciation in the Environment of Gold Tailings Dumps in the Central Rand, Johannesburg', in AB Fourie, M Tibbett, I Weiersbye & P Dye (eds), Mine Closure 2008: Proceedings of the Third International Seminar on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 673-680, https://doi.org/10.36487/ACG_repo/852_62



Abstract:
Mercury is present in the environment in different molecular forms with specific biogeochemical transformations and ecotoxicities. Inorganic Hg2+ is the main form in water and sediment samples. Special attention is given to transformations which lead to the in situ production of methylmercury. The concentrations of organomercury species are very low (usually ng/L) in environmental aquatic environments but the toxic effect of these species can be significant due to their tendency for bioaccumulation and biomagnification in the food chain. The determination of total concentrations of mercury is therefore not sufficient to understand its fate in the environment. The objectives of this study are to assess mercury and tin speciation in regions exposed to potential environmental pollution due to the reprocessing of old gold sand and slimes tailings dumps. Water, sediments, soils, aquatic green algae, common reeds and spinach plants were sampled and analyzed. The study included collection of ancillary data (pH and redox potential) which are critically important for mercury-monitoring programmes. The data will be used for a development of predictive models based on thermodynamic solution equilibria including transformations, transport, fate and biological uptake.

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