Wood treating

Lapacol [84-79-7] (Cl Natural Yellow 16 Cl 75490) (lapachic acid, taiguie acid, tecomin) is a yellow pigment occurring in the wood of trees of the genus Tecoma native to the West Indies and tropical South America. The shavings of the wood, treated with lime water, give an extract that dyes cotton yellow. 

The characterization of PIC (products of incomplete combustion) from the combustion of wood treated with pentachlorophenol (penta) is more widely documented in the open literature than creosote alone. However, both products are similar in chemical composition and likely result in comparable forms and concentrations of PIC. Literature reported studies on the combustion of these chemicals and wood treated by them, and the PIC generated are based upon optimal conditions. Optimal conditions are defined as those in which the fuel burns at the designed heat release rate with nominally 160% excess air and a low level (< 100 ppm) of carbon monoxide (CO) emissions in combustion (flue) gases. 

Table I. Octachlorodibenzo- >-dioxin Concentration before and after Burning Paper and Wood Treated with Pentachlorophenol and Sodium Pentachlorophenate...

Wood treated with paints, varnishes, and preservatives... 

Transfer of copper from wood treated with chromated copper arsenate (CCA) occurs in estuarine algae (Ulva, Enteromorpha), American oysters, mud snails (Nassarius obsoletus), and fiddler crabs (IJca spp. Weis and Weis 1992). Algae, barnacles, andmussels from CCA-treated lumber show elevated concentrations of copper when compared to reference sites. The epibiotic estuarine community that... 

In the United States, about 80% of the 23 million kg of technical PCP produced annually — or about 46% of worldwide production — is used mainly for wood preservation, especially utility poles (Pignatello etal. 1983 Kinzell etal. 1985 Zischke etal. 1985 Choudhury etal. 1986 Mikesell and Boyd 1986 USPHS 1994). It is the third most heavily used pesticide, preceded only by the herbicides atrazine and alachlor (Kinzell et al. 1981). Pentachlorophenol is a restricted-use pesticide and is no longer available for home use (USPHS 1994). Before it became a restricted-use pesticide, annual environmental releases of PCP from production and use were 0.6 million kg to the atmosphere from wood preservation plants and cooling towers, 0.9 million kg to land from wood preservation use, and 17,000 kg to aquatic ecosystems in runoff waters of wood treatment plants (USPHS 1994). There are about 470 wood preservative facilities in the United States, scattered among 45 states. They are concentrated in the South, Southeast, and Northwest — presumably due to the availability of preferred timber species in those regions (Cirelli 1978). Livestock facilities are often constructed of wood treated with technical PCP about 50% of all dairy farms in Michigan used PCP-treated wood in the construction of various components of livestock facilities (Kinzell et al. 1985). The chemical is usually applied to wood products after dilution to 5% with solvents such as mineral spirits, No. 2 fuel oil, or kerosene. More than 98% of all wood processed is treated with preservative under pressure about 0.23 kg of PCP is needed to preserve 1 cubic foot of wood (Cirelli 1978). Lumber treated with PCP retains its natural appearance, has little or no odor, and can be painted as readily as natural wood (Wood et al. 1983). 

This process uses a thermal treatment of wood impregnated with a chemically modified vegetable oil. It is claimed that wood treated using this process does not exhibit the usual reduction in mechanical properties associated with a thermal treatment. This process is at a pre-commercial pilot stage at the time of writing. 

Baysal, E., Ozaki, S.K. and Yalinkilic, M.K. (2004). Dimensional stabilisation of wood treated with furfuryl alcohol catalysed by borates. Wood Science and Technology, 38(6), 405 15. 

Bongers, H.P.M. and Beckers, E.P.J. (2003). Mechanical properties of acetylated solid wood treated on pilot plant scale. In Proceedings of the First European Conference on Wood Modification, Ghent, Belgium, Van Acker, J. and Hill, C.A.S. (Eds.), pp. 341-350. 

Dewispelaere, W., Raemdonck, J. and Stevens, M. (1977). Decay resistance of wood treated for dimensional stabilisation with monomers and formaldehyde. Material und Organismen, 12(3), 211-222. 

Razzaque, M.A. and Banks, W.B. (1982). Dimensional stability and sorption characteristics of wood treated with alkylene oxide. Bano Biggyan Patrika, 11(1/2), 17-23. 

Sailer, M., Rapp, A.O. and Peek, R.D. (1998). Biological resistance of wood treated with water-based resins and drying oils in a mini-block test. International Research Group on Wood Preservation, Doc. No. IRGAVP 98-10107. 

This area is undergoing huge developments at the present time, driven in part by environmental concerns regarding the use of wood treated with certain preservatives. There has been considerable commercial interest shown in wood modification over the past decade, with products based upon thermal modification and furfurylation now being actively marketed. The next few years will see the commercialization of acetylation and impregnation modification. This is a new industry, but one that has enormous potential. 

Think about the use to which the wood is to be put before deciding that you really need to have wood treated with preservatives. Consider how long the lumber needs to last. Tree stakes generally need only be in place for a couple of years, so using a treated stake that will survive for 25 years is totally unnecessary. Nonstructural lumber, such as bed edging and wood for a compost bin, could simply be left untreated. It will of course rot eventually, but you can then simply replace it. 

Sustainable woods treated only with eco-friendly products. 

Aspen Wood Treated with Chemical-Thermomechanical Process. Aspen wood was pulverized into "chemithermomechanical pulp (CTMP) by a chemical-thermomechanical process 24), During this process, very little hemicellulose and lignin are removed. The CTMP was used without any... 

The Implications of Environmental Weathering The Chemical Structure of Arsenic and Chromium in Wood Treated with CCA... 

The 7-7, Inc. (7-7) liquefication process was used at the Broderick Wood Products Superfund site, a former wood treating plant near Denver, Colorado. More than 3200 yd of creosote sludge were removed and recovered. The on-site liquefication of the sludge cost approximately 1,000,000. No information was available as to what these costs covered (D16170G). 

In 1993, a 60-kW system was used at a wood treating facility in Missouri to treat ground-water contaminated with PCP. This unit had operating costs of 1.30 per 1000 gal of water treated (D135159). 

This technology can remove oily sludges, pesticides, herbicides, pentachlorophenol, polychlorinated biphenyls (PCBs), coal by-products, wood treating compounds, dioxins, and furans. It is often used in conjunction with the company s base-catalyzed decomposition (BCD) process. The BCD process is designed to treat chlorinated compounds. 

ETG supplied thermal desorption technology at the Southern Maryland Wood Treating Superfund site. From 1997 through 2000, it was estimated that the thermal desorption costs at the site were 60,450,429 (including pending costs and potential modifications). The estimated completion cost for this application was 221 per ton. This was within 4% of the estimated cost in the record of decision (ROD) ( 214 per ton) (D22906L, p. 20). 

Closed-loop recovery of valuable chemicals and water can be performed by wood treating sites or chemical manufacturers. 

Chemical contaminants for which full-scale treatment data exist include primarily volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs). These SVOCs include polychlorinated biphenyls (PCBs), pentachlorophenol (PCP), pesticides, and herbicides. Extremely volatile metals, such as mercury and lead, can be removed by higher temperature thermal desorption systems. The technology has been applied to refinery wastes, coal tar wastes, wood-treating wastes, creosote-contaminated soils, hydrocarbon-contaminated soils, mixed (radioactive and hazardous) wastes, synthetic mbber processing wastes, and paint wastes. 

According to the vendor. Microbial Fence has been used to treat groundwater contaminated with polycyclic aromatic hydrocarbons (PAHs) benzene, toluene, ethylbenzene, and xylenes (BTEX) and volatile organic hydrocarbons (VOCs) at petroleum, chemical, and wood treating facilities and manufactured gas plants. Microbial Fence was used alone or in conjunction with soil venting/bioventing, aquifer aeration, pump-and-treat methods, and/or recovery of non-aqueous-phase liquids (NAPLs). 

The technology can be used to treat hydrocarbon-contaminated soils and sludges resulting from petroleum refining and marketing, wood treating, and petrochemical industry activities. The technology can also treat sediments. 

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