Wood Preservative Solutions for Creative and Sustainable Bridge Design and Construction

Timber bridges can provide an economical alternative to concrete and steel structures, particularly in rural areas where vehicle traffic is light to moderate. The wooden components of bridges have historically been preserved with either an oil type or waterborne preservative system to protect the wood from decay in order to maintain required performance standards for an extended period of time. The focus of this paper is to describe some of the key preservatives, research and case studies that support use of preserved wood, and some important steps to follow for the appropriate and safe use of preserved wood when the planned application will be in or over aquatic and wetland environments. A wealth of scientific information has been collected and analyzed that clearly suggests the use of preserved wood does not present a significant adverse effect on aquatic and wetland environments. This conclusion is based on two decades of empirical research and case study evaluating the environmental fate and effects of preserved wood, level of migration of contaminates into aquatic and marine environments, and the preserved wood environment. This is particularly true when risks are properly assessed on a project site, the appropriate preservative is selected and the wood is preserved to the Western Wood Preservers Institute＇s BMPs （best management practices）, along with properly installing and maintaining the preserved material. To assist with the assessment process, peer-reviewed risk assessment models for 11 commonly used preservatives have been developed that provide for streamlined data entry by users and allow for evaluation of a structure above and below water. A companion preliminary screening level assessment tool is also available. When these measures are properly utilized engineers, biologists and other responsible officials can be confident that the service life of the preserved wood components will more than likely meet the required performance standards in an environmentally safe manner for up to 50 or more years on a majority of timber bridge projects.

Fixation Property of Copper Triazole Wood Preservatives

According to AWPA E11-2006 standard,copper fixation rates of several copper-based formulations,such as ammoniacal copper,amine copper,and ammoniacal-ethanolamine copper,as well as alkaline copper quaternary(ACQ),were tested and compared in this paper.And the fixation rates of tebuconazole(TEB) and propiconazole(PPZ) in several formulations,such as copper azole,emulsified type and solvent type,were also compared.The determination of copper content in the leachate was analyzed by atomic absorption spectrom...

An Exploratory Analysis of the Market Perspective on Reclaiming Chromated Copper Arsenate (CCA) from Decommissioned Preservative-Treated Wood Utility Poles

In the area of recycling of spent chromated copper arsenate (CCA)-treated wood, most studies to date have focused on methods of removing/extracting the residual preservative from the wood matrix. It is well recognized that exposure of CCA-treated wood to an acid solution can reverse the CCA fixation process thereby converting the CCA elements into their water-soluble form. The economic viability of the process is enhanced because it can be integrated with other technologies and products (e.g., “green” spray foam insulation, etc.). The market for the “green” CCA is the same as for traditional CCA-the wood treating industry, principally utility poles and pilings. A market research study was conducted to determine the suitability of spent CCA-treated wood as a source for recycled, “green” CCA for manufacturing “green” spray-foam insulation. Specifically, we wanted to discern the attitudes and overall perspectives of buyers/sellers (i.e., utilities and wood treating companies) of CCA preservatives and treated wood products, disposal methods and costs for decommissioned CCA-treated wood, and understand perceptions of and willingness-to-pay for “green” CCA preservatives extracted from the technologies used in this research. Results show that 60% of wood preservative treating respondents and 60% of electric utility company respondents are somewhat or greatly interested in using out-of-service utility poles as feedstock for “green insulation” as part of a new potential business venture.

Repellent and Insecticidal Activity of Naphthoquinones from the Heartwood of Tectona grandis on Incisitermes marginipennis(Latreille)

Wood is a lignocellulosic material that,because of its organic nature,is a source of nutrients for bacteria,fungi,and insects.Incisitermes marginipennis(Latreille)is an interesting dry wood-boring termite.Because it is an extremely destructive pest,difficult to control due to its cryptic lifestyle,and for its role in the biogeochemical cycle of carbon and other elements;it is a fundamental organism.The use of less toxic and eco-friendly substances is important for protecting domestic,cultural,and historical heritage made of wood or lignocellulosic materials.The aim of this study was to evaluate the biological activity of various naphthoquinones extracted from the heartwood of T.grandis on I.marginipennis.First,heartwood flour was used for Soxhlet-type extractions to isolate and characterize the heartwood compounds by thin-layer chromatography.To identify the heartwood compounds,nuclear magnetic resonance and gas chromatography coupled to a mass spectrometer were used.The information obtained was supported using the Interactive Spectroscopy software.The identified heartwood compounds were lapachol,tectoquinone,deoxylapachol,dehydro-α-lapachone,tectol and tecomaquinone-I.Using nymphal termites of I.marginipennis as a biological model,the isolated and identified molecules were under three different tests(repellent,insecticide and protective)and their biological activity was individually evaluated.The results showed that the molecules obtained have a repellent-protective effect against I.marginipennis,although not in all cases,these molecules have high percentages of mortality and decreased the weight loss of the treated material exposed to I.marginipennis.

Inhibitory Effect of N,N-Dimethylhexadecylamine on the Growth of White-Rot Fungus Trametes versicolor(L.)in Wood

Wood is an organic material that is a source of carbon of organisms called Wood-decay fungi,and to preserve the wood,various toxic compounds to man and the environment have been used.To analyze the effect of N,NDimethylhexadecylamine(DMHDA)on wood attacked by the rotting fungus Trametes versicolor L.We used an in vitro system to expose the fungus T.versicolor to different concentrations of the DMHDA(50,150 and 450µM).We quantified the diameter of mycelial growth and laccase activity,also,under these experimental conditions we studied morphological details of the organisms using different scanning equipment including scanning electron microscopy.The growth of T.versicolor exposed to DMHDA for 60 days,showed a concentration-dependent dose behavior,also,the electron microscopy analysis revealed that the morphology and mycelial density was affected by the DMHDA,showing a formation of atypical morphological and thickener folds.Finally,the pieces of wood treated with DMHDA and exposed to the fungus had a lower mass loss,after a period of 60 days of exposure,the values obtained were 0.7,1.0 and 0.5 g of mass lost for the control,LoC and LoDMHDA treatments respectively.Wood-rot fungi have represented economic losses worldwide,the strategies used have been supported by toxic compounds for the environment.The DMHDA both in the Petri dish system and as a wood preservative was shown to significantly inhibit the growth of T.versicolor.

Effect of colloid-size copper-based pesticides and wood-preservatives against microbial activities of Gram-positive Bacillus species using five-day biochemical oxygen demand test

Copper-based pesticides and wood preservatives could end up in the environment during production,use,and end-of-life via different pathways that could cause unintended ecolog-ical and adverse health effects.This paper provides the effect of colloid-size Cu-based pesti-cides(CuPRO and Kocide),micronized Cu azole(MCA-1 and MCA-2)and alkaline Cu quater-nary(ACQ)treated woods,Cu^(2+),Cu^(2+) spiked untreated wood(UTW),and CuCO_(3) solutions against Gram-positive Bacillus species using five-day biochemical oxygen demand(BOD 5)stan-dard test.The total Cu leached from MCA-1,MCA-2,and ACQ in Milli-Q water after 5 days were -0.1,-0.11,and -0.64 g/kg of wood,respectively.However,the form of Cu leached from MCA woods was mostly ionic(>90%).The total organic carbon(TOC)content of any tested wood(UTW/MCA-1/MCA-2/ACQ)was -99%of its corresponding total carbon(TC)content,whereas the TOC of any tested wood sawdust exceeded that of its corresponding piece/block by>300%.The dissolved oxygen(DO)consumption value in the presence of Cu^(2+),CuCO_(3),CuPRO,and Kocide solutions was significantly influenced by Cu particles/ions.However,the DO consumption value in the presence of UTW/MCA-1/MCA-2/ACQ woods was significantly influenced by organics leached from woods.On the other hand,the DO consumption of MCA sawdust was greater than(300%)that of MCA pieces/block.The findings of this study provide more insight into how organics leached from woods significantly reduce the toxic effects of Cu ions against Gram-positive Bacillus species.

Mechanical properties,components and decay resistance of Populus davidiana bioincised by Coriolus versicolor

The experiment was conducted to improve the decay resistance of wood by increasing the wood preservatives uptake and penetration depth by bioincising with Coriolus versicolor.The mechanical properties of bioincised Populus davidiana sapwood were measured.The changes of wood components(lignin,cellulose and hemicellulose)were analyzed by FTIR.The staining treatment using potassium permanganate was to measure the preservatives uptake and penetration depth in wood specimens.The decay resistance of bioincised specimens impregnated with IPBC and CA was assessed against C.versicolor and Gloeophyllum trabeum using bioincised P.davidiana sapwood and untreated controls.The results showed that the mechanical properties of the bioincised specimens were changed with the incubation time and mass loss.The mechanical strength was decreased after 17 days compared to that of the specimens bioincised<13 days.The bioincised specimens demonstrated the deeper penetration depth than the un-bioincised specimens.It was significant correlation(P<0.01)between penetration depth and incubation time.The average value of the penetration depth of the bioincised specimens was deeper than the control groups by 158.7%.By FTIR analysis,the biodegradation ability of C.versicolor to decay cellulose and hemicellulose was weaker than that of lignin.The bioincising treatment significantly increased the wood uptake of IPBC and CA,and reached the maximum uptake value at 17 and 13 days,respectively.Summarily,the bioincising pretreatment can obviously improve the wood decay resistance against C.versicolor and G.trabeum following by introducing the IPBC and CA.

Impact Evaluation of a Project on Alternative Energy ＂Biogas Plants＂ in Sindh, Pakistan

The core purpose of impact study was to collect best practices learnings of project through the reflection of communities or end users. During analysis and interpretation of data, some touch of context is also given to clear the picture of weakness and strengths of project theory in terms of context. The main objective of project under study was to provide alternative energy to the communities living inside forest to reduce wood cutting for domestic purpose. Though there were many short term surveys were conducted during project, such as, average wood consumption at household level, community motivation survey. Instead to all MRDS （Mehran Research ＆ Development Society） felt need to conduct a detailed impact evaluation to see overall impact of project implementation and review on the life of end users or communities. After three years of project exit, MRDS conducted a qualitative impact study of project in the end of 2014. There were three key questions to explore during study： What was the overall impact of project on end users？ What the best practices of project and why？ What are project learnings and how？

Full scale amendment of a contaminated wood impregnation site with iron water treatment residues

Iron water treatment residues （Fe-WTR） are a free by-product of the treatment of drinking water with high concentration of iron oxides and potential for arsenic sorption. This paper aims at applying Fe- WTR to a contaminated site, measuring the reduction in contaminant leaching, and discussing the design of delivery and mixing strategy for soil stabilization at field scale and present a cost-effective method of soil mixing by connnon contractor machinery. Soil contaminated by As, Cr, and Cu at an abandoned wood impregnation site was amended with 0.22% （dw） Fe-WTR. To evaluate the full scale amendment a 100 mtest site and a control site （without amendment） were monitored for 14 months. Also soil analysis of Fe to evaluate the degree of soil and Fe-WTR mixing was done. Stabilization with Fe-WTR had a significant effect on leachable contaminants, reducing pore water As by 93%, Cu by 91% and Cr by 95% in the upper samplers. Dosage and mixing of Fe-WTR in the soil proved to be difficult in the deeper part of the field, and Pire water concentrations of arsenic was generally higher.Despite water logged conditions no increase in dissolved iron or arsenic was observed in the amended soil. Our field scale amendment of contaminated soil was overall successful in decreasing leaching of As, Cr and Cu. With minor improvements in the mixing and delivery strategy, this stabilization method is suggested for use in cases, where leaching ofCu, Cr and As constitutes a risk for groundwater and freshwater.