Treesearch

Pesticide entrainment in stormwater runoff can contribute to non-point source pollution of surface waters. Granular activated carbon has been successfully used for removing pesticides from wastewater. However, implementation of granular activated carbon sorption media in stormwater filtration systems comes with high initial capital investment and operating costs. Modified pine barks offer attractive alternative sorption media for use in stormwater filtration systems. Pine barks constitute a significant fraction of underutilized low-value waste materials from the forest products industry....

When wood is exposed to various environmental conditions, many degradation reactions (biological, ultraviolet, mechanical, moisture, and chemical) can occur. To protect wood from biological degradation, chemical preservatives are applied by nonpressure or pressure treatment. Penetration and retention of a chemical depend upon the wood species and the amount of heartwood (more difficult to treat) or sapwood (easier to treat). The objective of adding preservatives is to achieve long-term effectiveness for the wood product, thus sequestering (capturing and storing) carbon.

The increase in the use of non-arsenical copper-based wood preservatives in response to environmental concerns has been accompanied by interest in copper-tolerant decay fungi. Oxalic acid production by brown-rot fungi has been proposed as one mechanism of copper tolerance. Fifteen brown-rot fungi representing the genera Postia, Wolfiporia, Meruliporia, Gloeophyllum, Laetiporus, Coniophora, Antrodia, Serpula, and Tyromyces were evaluated for oxalic acid production bi-weekly in southern yellow pine (SYP) blocks treated with 1.2% ammoniacal copper citrate (CC). Eleven fungi were designated...

Accumulation of oxalic acid (OA) by brown-rot fungi and precipitation of copper oxalate crystals in wood decayed by copper-tolerant decay fungi has implicated OA in the mechanism of copper tolerance. Understanding the role of OA in copper tolerance is important due to an increasing reliance on copper-based wood preservatives. In this study, four copper-tolerant brown- rot fungi were evaluated for decay capacity and OA production in early stages of exposure to four waterborne copper-based wood preservatives (ammonical copper quat type B and D, ammonical copper citrate, and chromated copper...

The phase reaction conversion (PRC) headspace gas chromatographic (HSGC) technique was employed to develop a method for the determination of the content of carboxyl groups in wood fibers. Acid treatment of the wood fibers using hydrochloric was applied to convert carboxyl groups to carboxyl acids. Bicarbonate solution is then used to react with carboxyl acids on the treated fibers in the headspace of a testing vial to form carbon dioxide that is analyzed by a thermal conductivity detector using gas chromatography. The conversion reaction was conducted at 60oC for about 10 minutes to...

Options for recycling and reusing chromated-copper-arsenate- (CCA) treated material include dimensional lumber and round wood size reduction, composites, and remediation. Size reduction by remilling, shaving, or resawing CCA-treated wood reduces the volume of landfilled waste material and provides many options for reusing used treated wood. Manufacturing composite products from CCA-treated wood combined with untreated wood, plastic, or cement has been explored. Remediation strategies are numerous; chemical extraction, bioleaching, chelation, and liquefaction or a combination of these...

It has been found that polyoxometalates (POMs) can act as mediators in the electrochemical oxidation of lignin in pulps. An electrochemical cell, with a Nafion® membrane separating the anode and cathode compartments, was used in the delignification experiments. A softwood kraft pulp was placed in the anode compartment with a buffered 0.01M solution of the polyoxometalate Na5[SiVW11O40]. During electrolysis the lignin content of the pulp was reduced from kappa number 26 to 6. The energy required for this delignification was equivalent to 120 kW·hr per ton of pulp. At $0.05/ kW·hr, the cost...

Because radiata pine has thrived in south-central Chile since it was introduced there more than a century ago, pine plantation productivity there has grown tremendously. Plantation owners are seeking new markets for this material. One potential market is utility poles. The American National Standards Institute 05.1 standard (ANSI 05.1) provides a means for radiata pine to be recognized as a viable pole species. Before radiata pine can be accepted into ANSI 05.1, test data must be provided to support the ANSI-designated fiber stress. This studypresents an evaluation of radiatapine poles...

The principal wood preservative for residential use is currently a broad-spectrum biocide which contains As, Cr and Cu. However, the use of totally organic wood preservative systems in certain applications or localities may be required in the future. This will greatly increase the price of treated wood. The combination of organic biocides with non-biocidal additives to give enhanced efficacy is one possible means to lower the cost of future wood preservative systems. Possible non-biocidal additives which could be mixed with organic biocides include water repellents, antioxidants, and...

Early detection of wood decay can prolong the service life of wood. Antibodies are the ideal probe for detecting fungi that cause biodeterioration because they are highly specific and can quantitatively determine the fungal antigen concentration from highly complex structures, such as wood. Polyclonal antibodies recognize multiple chemical sites of the targeted molecule, in our case, a fungal glycoprotein, while monoclonal antibodies recognize one specific protein sequence on the targeted molecule. Both polyclonal and monoclonal antibodies have been utilized separately or in concert to...