The effect of soil type on copper leaching from wood treated with three copper-based wood preservatives

In this study, Scots pine (Pinus sylvestris L.) wood samples were treated with 3 different major wood preservatives (alkaline copper quaternary (ACQ), copper chrome boron (CCB) and copper azole (CuA)). Treated wood samples were subjected to 1 and 3 months of leaching in 3 different soil types and the amount of leached heavy metal Cu was determined on a laboratory scale. In addition, wood samples were exposed to white rot (Trametes versicolor) and brown rot (Neolentinus lepideus) fungi after leaching and weight losses were calculated. At the end of the 1 and 3 months of leaching period, the soil samples were taken from the pots and the amount of Cu was determined. The lowest Cu content (4.3 mg/kg) was detected in the samples treated with CCB among the wood preservatives, while the highest content (196.3 mg/kg) was determined in ACQ. The lowest Cu amount was determined in loamy sand soil type and the highest Cu amount was determined in clay loam soil type. According to the findings from the current study, leaching in soil did not affect weight losses caused by T. versicolor, while significant weight losses occurred by N. lepideus. This study indicated that loamy sand soil is more suitable for the treated wood if there is a risk regarding leaching.