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

Mercer, Theresa and Frostick, L.E. (2012) Leaching characteristics of CCA-treated wood waste: A UK study. Science of the Total Environment, 427 . pp. 165-174. ISSN 0048-9697

Full content URL: https://doi.org/10.1016/j.scitotenv.2012.04.008

Leaching characteristics of CCA-treated wood waste: A UK study
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CCA-treated wood is expected to increase in the UK waste stream over the next 20–50 years. 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 1885 μg/l, 1243 μg/l and 1261 μg/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.

Keywords:All metal, Batch leaching, CCA treated wood, Human health, Leaching characteristics, Leaching process, Mobile species, Monofills, Mulch, Peak concentrations, Potential impacts, Regulatory thresholds, Soil water, Temporal trends, Three orders of magnitude, Treated wood, Waste stream, Waste wood, Wood mulch, Arsenic, Chromium, Lysimeters, Pollution, Soil moisture, Soil surveys, Soils, Wood, Leaching, arsenic, chromated copper arsenate, copper, rain, unclassified drug, wood protecting agent, arsenic, concentration (composition), leaching, lysimeter, weathering, agricultural waste, article, diffusion, lysimetry, priority journal, United Kingdom, water pollution, weathering, wood waste, Arsenates, Environmental Monitoring, Mass Spectrometry, Soil Pollutants, Spectrophotometry, Atomic, Waste Products, Water Pollutants, Chemical, Wood, Arsenic, Moisture, Soil, Surveys, Wood, Wood Waste, United Kingdom
Subjects:F Physical Sciences > F851 Applied Environmental Sciences
F Physical Sciences > F140 Environmental Chemistry
Divisions:College of Science > School of Geography
ID Code:34051
Deposited On:22 Nov 2018 17:16

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