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Leaching characteristics of CCA-treated wood waste: A UK study

Mercer, T. G.; Frostick, L. E.

Authors

T. G. Mercer

L. E. Frostick

Abstract

CCA-treated wood is expected to increase in the UK waste stream over the next 20-50years. The potential pollution from this waste has been evaluated through two leaching studies, one based upon batch leaching tests and another based upon a series of lysimeter tests. The aim of the studies was to characterise the behaviour of arsenic (As), chromium (Cr) and copper (Cu) from this wood when applied to soil as a mulch. Results demonstrate that all three elements leach from CCA waste wood, occasionally in concentrations exceeding regulatory thresholds by two to three orders of magnitude. In the lysimeter study, wood mulch monofills and wood mulch in combination with soil were used to monitor the leaching of As, Cr and Cu. Peak concentrations for As, Cr and Cu were 1885μg/l, 1243μg/l and 1261μg/l, respectively. Freshly treated wood leached 11, 23 and 33 times more Cu, Cr and As, respectively than weathered wood. The toxic and mobile species of arsenic (As III, As V) were detected. Leaching in the CCA wood monofill was influenced by rainfall, with higher concentrations of metal(loid)s produced in lower intensity events. As and Cu were mobilised preferentially, with all metals exhibiting similar temporal trends. Retention of leached metal(loid)s was observed in lysimeters containing soil. Leaching processes appear to be favoured by the chipping process, diffusion and weathering. This study has shown that weathered waste wood mulch can cause significant pollution in soil water with potential impacts on both the environment and human health.

Journal Article Type Article
Publication Date Jul 15, 2012
Journal Science Of The Total Environment
Print ISSN 0048-9697
Electronic ISSN 1879-1026
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 427-428
Pages 165-174
Institution Citation Mercer, T. G., & Frostick, L. E. (2012). Leaching characteristics of CCA-treated wood waste: A UK study. The Science of the total environment, 427-428, (165-174). doi:10.1016/j.scitotenv.2012.04.008. ISSN 0048-9697
DOI https://doi.org/10.1016/j.scitotenv.2012.04.008
Keywords Environmental Engineering; Waste Management and Disposal; Pollution; Environmental Chemistry
Publisher URL https://www.sciencedirect.com/science/article/pii/S0048969712005037?via%3Dihub
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