Contrasting controls on arsenic and lead budgets for a degraded peatland catchment in Northern England.

Autor: Rothwell JJ; Upland Environments Research Unit, School of Environment and Development, The University of Manchester, Manchester M13 9PL, UK. james.rothwell@manchester.ac.uk, Taylor KG, Evans MG, Allott TE
Jazyk: angličtina
Zdroj: Environmental pollution (Barking, Essex : 1987) [Environ Pollut] 2011 Oct; Vol. 159 (10), pp. 3129-33. Date of Electronic Publication: 2011 Jun 16.
DOI: 10.1016/j.envpol.2011.05.026
Abstrakt: Atmospheric deposition of trace metals and metalloids from anthropogenic sources has led to the contamination of many European peatlands. To assess the fate and behaviour of previously deposited arsenic and lead, we constructed catchment-scale mass budgets for a degraded peatland in Northern England. Our results show a large net export of both lead and arsenic via runoff (282 ± 21.3 gPb ha(-1) y(-1) and 60.4 ± 10.5 gAs ha(-1) y(-1)), but contrasting controls on this release. Suspended particulates account for the majority of lead export, whereas the aqueous phase dominates arsenic export. Lead release is driven by geomorphological processes and is a primary effect of erosion. Arsenic release is driven by the formation of a redox-dynamic zone in the peat associated with water table drawdown, a secondary effect of gully erosion. Degradation of peatland environments by natural and anthropogenic processes has the potential to release the accumulated pool of legacy contaminants to surface waters.
(Copyright © 2011 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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