Properties of particleboard made from recycled CCA-treated wood

Recovery of chromated copper arsenate (CCA)-treated wood for reuse has been the focus of several international research groups due to the imminent disposal problem created when large quantities of CCA-treated wood ultimately come out of service. Bioleaching with Bacillus licheniformis CC01 and oxalic acid extraction are two methods known to remove significant quantities of metals from CCA-treated wood. Remediated particulate CCA-treated southern pine was reassembled into particleboard (PB) using 10% urea-formaldehyde resin. Particleboard panels were evaluated for internal bond (IB), modulus of elasticity (MOE), modulus of rupture (MOR), thickness swell (TS) and water absorption compared to particleboard manufactured from virgin southern pine and CCA-treated southern pine. Particleboard panels prepared from the remediated chips showed an average 28% reduction in IB and a 13% reduction in MOR compared to values for PB prepared with virgin chips under the pressing parameters used in this study, though individual IB values for all specimens were above the ANSI standard for medium density particleboard. An 8% increase in MOE in the remediated chip PB compared to the virgin chip PB may indicate densification of the fiber surface as a result of the acid extraction step of the remediation process. Thickness swell and water absorption after 24-hour submersion also increased in PB prepared from remediated chips (15% and 14%, respectively). We conclude that pressing parameter optimization could alleviate decreases in MOR and IB seen in PB made from remediated chips, and that the effects of acid extraction on MOR and IB properties should be further evaluated.