Search Results (10)

This study presents the Wood Protection Sustainability Index (WPSI), a novel decision-support tool aimed at evaluating wood preservatives utilized in Chile and facilitating a shift toward more sustainable wood protection practices. WPSI encompasses four essential attributes: protection treatment, wood durability, in-service risk, and sustainability. These are assessed under two distinct scenarios. Scenario 1 represents current market practices, where chromated copper arsenate (CCA) remains prevalent due to its accessibility and affordable cost. In contrast, Scenario 2 prioritizes sustainability, demonstrating that copper azole (CA) and alkaline copper quaternary (ACQ) surpass CCA in performance, with CCA ranking lowest due to its environmental implications. Furthermore, a SWOT analysis accompanies the index, identifying key challenges and opportunities within Chile’s wood preservation industry. The findings highlight the importance of aligning national strategies with Environmental, Social, and Governance (ESG) frameworks, as well as the Sustainable Development Goals (SDGs), through performance-based regulations and safer alternatives. The WPSI can be integrated with local standards, regional risk classifications, and national preservative approval systems, allowing for meaningful comparison across diverse global contexts. This approach promotes more sustainable construction practices while ensuring both technical and economic viability. Full article

Logs supplied in Papua New Guinea and Indonesia are predominantly sourced from fast-growing tree species of plantation forests. The timber primarily consists of sapwood, which is highly susceptible to biodeterioration. At a training center, CCA (chromated copper arsenate) is still used for wood preservation, while in the wood industry, ACQ (alkaline copper quaternary) is commonly applied to enhance the service life of timber. In the future, polystyrene impregnation or other non-biocidal treatments could potentially serve this purpose. This study aimed to determine the discoloration and resistance of polystyrene-impregnated and CCA-preserved woods. Wood samples, Anisoptera thurifera and Octomeles sumatrana from Papua New Guinea, and Anthocephalus cadamba and Falcataria moluccana from Indonesia, were used. The wood samples were treated with polystyrene impregnation, CCA preservation, or left untreated, then exposed at the PNG Forest Research Institute site for four months. After treatment, the color change in polystyrene-impregnated wood was minor, whereas CCA-preserved wood exhibited a noticeably different color compared to untreated wood. The average polymer loading for polystyrene-impregnated wood reached 147%, while the average CCA retention was 8.4 kg/m³. Densities of untreated-, polystyrene-, and CCA-wood were 0.42, 0.64, and 0.45 g/cm³, respectively, and moisture contents were 15.8%, 9.4%, and 13.4%, respectively. CCA preservation proved highly effective in preventing termite attacks; however, CCA is hazardous to living organisms, including humans. Polystyrene impregnation also significantly improved wood resistance to subterranean termites, as indicated by lower weight loss and a higher protection level compared to untreated wood. Additionally, polystyrene treatment is nonhazardous and safe for living organisms, making it a promising option for enhancing wood resistance to termite attacks in the future as an alternative to the biocides currently in use. Full article

Wood is an essential construction material because of its renewable nature, versatility, and ability to store carbon, which aids in climate change mitigation. However, its biodegradability requires preservation treatments to prolong its service life and improve its durability. This study compares international wood preservation regulations with the Chilean framework and evaluates their alignment with Environmental, Social, and Governance (ESG) criteria and the Sustainable Development Goals (SDGs). The findings reveal a global trend focused on reducing hazardous preservatives like chromated copper arsenate (CCA) while promoting environmentally friendly alternatives. The discussion emphasizes the need for strategic regulatory updates and investment in sustainable wood protection technologies. These efforts are essential for ensuring long-term structural performance, resource efficiency, and market competitiveness. Full article

Due to the inherent metals (Cu, As and Cr) in preserved wood waste (CCA-treated wood waste) that pose a risk to both the environment and human health, it is crucial to dispose of CCA-treated wood properly. Carbon materials have received widespread attention for their high porosity, renewability and simplicity of fabrication. This work presents a simple and effective process for producing carbon materials from leftover CCA-treated wood (chromated copper arsenate). Utilizing CCA-treated wood derived carbon (CCA-BC) and activating it with KOH (CCA-AC), electrode materials for supercapacitor applications were created and its electrochemical characteristics were investigated. The resulting material combines the conductivity of the metal in preserved wood with the good porosity provided by carbon materials. Compared with common wood biomass, carbon (W-BC) and common wood activated carbon (W-AC), CCA-BC and CCA-AC have better electrochemical properties. After being pyrolyzed at 600 °C for two hours, CCA-AC performed optimally electrochemically in 1 M Na₂SO₄ electrolyte, demonstrating a 72% capacity retention rate after 2000 charge and discharge cycles and a specific capacity of 76.7 F/g. This study provides a novel approach for the manufacture of supercapacitor electrodes, which also allows preserved wood waste an environmentally nondestructive form of elimination. Full article

The widespread use of wood preservatives, such as chromated copper arsenate (CCA), alkaline copper quaternary (ACQ), and copper azole (CA), may cause environmental pollution problems. Comparative studies on the effect of CCA-, ACQ-, and CA-treated wood on soil contamination are rarely reported, and the behavior of soil metal(loid) speciation affected by preservatives has been poorly understood. Soils under the CCA-, ACQ-, and CA-treated boardwalks were collected to investigate metal(loid) distribution and speciation at the Jiuzhaigou World Natural Heritage site. The results showed that the maximum mean concentrations of Cr, As, and Cu were found in soils under the CCA, CCA, and CCA plus CA treatments and reached 133.60, 314.90, and 266.35 mg/kg, respectively. The Cr, As, and Cu contamination in soils within a depth of above 10 cm was high for all types of boardwalks and limited in the horizontal direction, not exceeding 0.5 m. Cr, As, and Cu in soils were mainly present as residual fractions in all profiles and increased with depth. The proportion of non-residual As in soil profiles under CCA- and CCA plus CA-treatment and exchangeable Cu in CA- and CCA plus CA-treatment were significantly higher than those in the profiles under the other preservative treatments. The distribution and migration of Cr, As, and Cu within soils were influenced by the preservative treatment of trestles, in-service time of trestles, soil properties (e.g., organic matter content), geological disasters (e.g., debris flow), and elemental geochemical behavior. With the CCA treatment for trestles successively replaced by ACQ and CA treatments, the types of contaminants were reduced from a complex of Cr, As, and Cu to a single type of Cu, achieving a reduction in total metal content, toxicity, mobility, and biological effectiveness, thus reducing environmental risks. Full article

Plywood is widely used in civil construction. Due to the importance of preservation and gluing in bio-composites, this study compares the influence of a chemical treatment with CCA (chromated-copper-arsenate) on Pinus taeda L. wood veneers to produce two plywood types using phenol-formaldehyde (PF) and castor oil-based polyurethane (PU). Four different treatments were performed to analyze both varieties’ physical and mechanical properties. As a result, an improvement in the properties of the treated panels was observed. Lower moisture contents and better interactions caused by less thickness swelling and water absorption were identified in the PU-based plywoods. The treatment with CCA was efficient, improving these properties when they were compared to the reference panels. Most treatments evidenced increases in the modulus of elasticity and modulus of rupture for both adhesives when the CCA treatment was applied to the veneers. Comparing the resins, the PF showed the best values of modulus of elasticity. All treatments met the requirements defined by the Brazilian standard document for the glue line shear. Full article

Pentachlorophenol and chromated copper arsenate (CCA) have been used worldwide as wood preservatives, but these compounds can toxify ecosystems when they leach into the soil and water. This study aimed to evaluate the capacity of four treatment wetland macrophytes, Phalaris arundinacea, Typha angustifolia, and two subspecies of Phragmites australis, to tolerate and treat leachates containing wood preservatives. The experiment was conducted using 96 plant pots in 12 tanks filled with three leachate concentrations compared to uncontaminated water. Biomass production and bioaccumulation were measured after 35 and 70 days of exposure. There were no significant effects of leachate contamination concentration on plant biomass for any species. No contaminants were detected in aboveground parts of the macrophytes, precluding their use for phytoextraction within the tested contamination levels. However, all species accumulated As and chlorinated phenols in belowground parts, and this accumulation was more prevalent under a more concentrated leachate. Up to 0.5 mg pentachlorophenol/kg (from 81 µg/L in the leachate) and 50 mg As/kg (from 330 µg/L in the leachate) were accumulated in the belowground biomass. Given their high productivity and tolerance to the contaminants, the tested macrophytes showed phytostabilization potential and could enhance the degradation of phenols from leachates contaminated with wood preservatives in treatment wetlands. Full article

Traditional benchmark wood durability testing methods such as stake tests take many years to give conclusive results, and in-ground tests do not always indicate the efficacy of preservatives in above-ground situations. To find test methods that would shorten the time required for wood evaluation for above-ground end uses, a series of different types of accelerated durability tests were set up. Five types of test: ground proximity, two types of decking, flat panels and double layer, were reassessed after ten years to determine whether the decay rankings given to the various types of preservative had changed over the extended exposure period. Exposure conditions varied between tests, with ground proximity being close to ground, and the double layer test carried out in very wet conditions, while raised decking and flat panel tests were relatively dry. In all of these tests, the preservative retention was 25% of the normal H3 retention. The results indicated that the ground proximity tests gave the fastest and most reliable results. Flat panels contained the next highest decay rates, followed by ground-level decking, double layer and raised decking. The evaluation and comparison of these five test methods after ten years’ field exposure confirmed the trend and relative decay rate that was observed at four-year exposure. The use of a regression model for prediction showed a statistically significant overall relationship between decay scores in 2011 and 2017 (coefficient = 0.14 ± 0.07, d.f. = 345.7, t = 2.038, p = 0.042). When resistance to decay was compared between preservatives, copper-chrome arsenate (CCA)-treated pine and naturally durable spotted gum samples were in better conditions than pine treated with any of the other preservatives. Full article

The highly toxic Cr(VI) is a critical component in the Chromated Copper Arsenate (CCA) formulations extensively employed as wood preservatives. Remediation of CCA mixed waste and discarded treated wood products is a significant challenge. We demonstrate that UV/TiO₂ photocatalysis effectively reduces Cr(VI) to less toxic Cr(III) in the presence of arsenate, As(V), and copper, Cu(II). The rapid conversion of Cr(VI) to Cr(III) during UV/TiO₂ photocatalysis occurs over a range of concentrations, solution pH and at different Cr:As:Cu ratios. The reduction follows pseudo-first order kinetics and increases with decreasing solution pH. Saturation of the reaction solution with argon during UV/TiO₂ photocatalysis had no significant effect on the Cr(VI) reduction demonstrating the reduction of Cr(VI) is independent of dissolved oxygen. Reduction of Cu(II) and As(V) does not occur under the photocatalytic conditions employed herein and the presence of these two in the tertiary mixtures had a minimal effect on Cr(VI) reduction. The Cr(VI) reduction was however, significantly enhanced by the addition of formic acid, which can act as a hole scavenger and enhance the reduction processes initiated by the conduction band electron. Our results demonstrate UV/TiO₂ photocatalysis effectively reduces Cr(VI) in mixed waste streams under a variety of conditions. Full article

The objective of this paper was to provide a preliminary analysis of the utilization of energy derived from waste wood in Taiwan, a highly industrialized country with a high dependence (over 99%) on imported energy. The discussion focuses on the status of waste wood generation and its management over the past decade. Findings show that the quantities of biomass waste collected for reuse purposes in the industrial sectors of Taiwan has exhibited an increasing trend, from about 4000 tons in 2001 to over 52,000 tons in 2010. Although waste wood can be reused as a fuel and raw material for a variety of applications based on regulatory promotion, the most commonly used end use is to directly utilize it as an auxiliary fuel in industrial utilities (e.g., boilers, heaters and furnaces) for the purpose of co-firing with coal/fuel oil. The most progressive measure for promoting biomass-to-power is to introduce the feed-in tariff (FIT) mechanism according to the Renewable Energy Development Act passed in June 2009. The financial support for biomass power generation has been increasing over the years from 0.070 US$/kWh in 2010 to 0.094 US$/kWh in 2012. On the other hand, the environmental regulations in Taiwan regarding the hazard identification of wood-combusted ash (especially in filter fly-ash) and its options for disposal and utilization are further discussed in the paper, suggesting that waste wood impregnated with chromated copper arsenate (CCA) and other copper-based preservatives should be excluded from the wood-to-energy system. Finally, some recommendations for promoting wood-to-energy in the near future of Taiwan are addressed. Full article