Migration of arsenic from old tailings ponds-A case study on the King Edward Mine, Cornwall, UK
- National Institute of Chemistry (Kiribati), Hajdrihova 19, SI-1001 Ljubljana (Slovenia)
- Jozef Stefan Institute (JSI), Jamova 39, SI-1000 Ljubljana (Slovenia)
- University of Exeter in Cornwall (UEC), Tremough Campus, TR10 9EZ Penryn, Cornwall (United Kingdom)
A methodology is presented to study the physico-chemical processes in old tailings ponds using an array of analytical-physical chemistry approaches. A case study was conducted on the sorption/desorption behaviour of arsenic in tailings pond 2406, at the King Edward Mine (KEM) in Cornwall, UK. The tailings pond was in operation from approximately 1907 to 1921. The methodology involves two principal stages: (1) sequential extraction followed by subsequent arsenic species determination to characterise the material with regards to the association of arsenic with soil phases and identification of As (III/V) in the easily accessible soil phase; (2) batch contacting/equilibrating the tailings pond material with As(III/V), followed by a similar procedure as in stage 1 to establish the material's As(III/V) phase distribution kinetics/thermodynamics. By extrapolating the data from present day samples we infer past and future elemental mobility. From this study it is concluded that adsorption and desorption from tailings material is a rapid process for the most unstable soil phases (non-specific and specific) and a slow process for the more stable phases (poorly crystalline and well crystalline). The hypothetical application of this conclusion to the tailings from dam 2406 is that, during the initial phases of the dam's creation (ca. 100 years ago), when arsenic was both in solution and bound to mineralogical components, arsenic must have dispersed into the environment as a result of slow As(V) adsorption/phase distribution processes. Aging of the tailings material sees the movement of the arsenic to the more stable soil phases, producing a situation that is seen at present day.
- OSTI ID:
- 21130768
- Journal Information:
- Environmental Research, Vol. 108, Issue 1; Other Information: DOI: 10.1016/j.envres.2008.05.002; PII: S0013-9351(08)00125-4; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0013-9351
- Country of Publication:
- United States
- Language:
- English
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