Дисертації з теми "CCA wood"

Chromated copper arsenate (CCA) is a biocidal chemical used by the wood preservation industry to extend the service life of wood products. CCA is currently the most commonly used wood preservative in British Columbia. Environmental concerns regarding the fate of CCA solutions accidentally released or chronically spilled to unpaved ground at wood preservation facilities has led to the present investigation on the retention and release of CCA constituents in soils. Batch and column tests were used to evaluate the adsorption and desorption of arsenic, chromium and copper in several B.C. soils. Batch tests were carried out using varying concentrations of CCA and individual arsenic, chromium and copper solutions. Migration of arsenic, chromium and copper in a soil column following application of a single slug dose of 2% CCA solution was investigated. Continuous leach column experiments were also conducted to evaluate adsorption of CCA constituents in soils. The column soils were sectioned and subjected to a sequential extraction procedure following influent CCA solution breakthrough to determine the partitioning, mobility and availability of As, Cr and Cu. Results from the adsorption experiments were used to identify important soil characteristics influencing the attenuation of CCA in the subsurface environment. Adsorption isotherm data was found to be well described by the Freundlich equation. The Fe and Al amorphous and crystalline hydrous oxide component of the soils studied was highly correlated with arsenic adsorption while the percent organic carbon was significantly correlated with chromium and copper retention in the soils. The clay content of the soils was poorly correlated with retention of CCA constituents in the soils studied. Desorption of arsenic, chromium and copper from soils previously equilibrated with CCA solutions showed that the extent of metal release is dependent on the amount of metal retained. At high initial CCA solution concentrations chromium was desorbed to a greater extent than arsenic or copper. This result suggests the following order for mobility of CCA constituents in the soils: chromium > copper > arsenic. Chromium, and to a lesser extent copper, adsorption was lower in CCA equilibrated batch tests than in single solute batch tests, particularly at high initial metal solution concentrations. Arsenic adsorption was not affected by the presence of codissolved solutes in CCA solution. The migration of arsenic, chromium and copper in a soil column following application of a single dose of 2% CCA revealed that chromium was the most mobile of the CCA constituents. Breakthrough curve plots showed that arsenic was the most strongly retained CCA constituent in both soils tested. Copper was also strongly retained in the soil columns however complete breakthrough was achieved indicating that the soils had reached a finite capacity for copper retention. Chromium was again the most weakly held CCA constituent in the continuous leach column test. Partitioning of the metals in the column soils showed that arsenic, chromium and copper were largely associated with the ammonium oxalate extractable fraction. Only copper was found to have a significant amount of retained metal in the exchangeable pool. The results suggest that environmental monitoring at CCA wood preservation facilities should focus on the potential for chromium migration in the subsurface.
Land and Food Systems, Faculty of
Graduate

The amount of CCA treated wood being removed from spent residential decks is increasing at a tremendous rate. While most spent CCA treated wood is being disposed in landfills, further useful and environmentally beneficial alternatives have to be met. This research estimated the percentage of recoverable lumber from spent CCA decks that can be recycled into other usable products. Six residential decks were removed from service, by either demolition or deconstruction procedures. It was found that 86% of the CCA treated wood from the residential decks could be recovered as reusable CCA treated lumber. It was also found that deconstruction of a residential deck, rather than demolition, was not a factor in the volume of CCA treated wood recovered. Chemical and mechanical properties of the removed CCA treated wood were also analyzed. The chemical retention of the deck material proved that most of the spent CCA treated wood could be used in above ground applications. The stiffness of spent CCA treated wood from residential decks was approximately equal to that of recently treated CCA wood. The strength properties were slightly lower than recently treated CCA wood probably due mainly to physical and climatic degradation. Products were then produced that could be successfully utilized by recycling centers or community and government organizations. Products manufactured included, pallets, picnic tables, outdoor furniture, residential decks, and landscaping components. Waste management, recycling, and government organizations were interviewed to determine what markets and barriers exist for recycled CCA treated products. Most landfill and recycling facilities do not currently sort or recycle CCA treated wood, citing the main reason as a lack of a viable market. Potential users were interested in the material but citied they did not know where to locate the material. A communication barrier exists between the waste management industry, recyclers, and users; which is preventing the successful recycling of CCA treated wood from spent residential decks.
Master of Science

Os postes de madeira da rede de distribuição de energia elétrica são tratados com preservantes para aumentar sua vida útil. Dentre os diversos tipos de preservantes de madeira disponíveis no mercado, o mais utilizado é o arseniato de cobre cromatado (CCA), tendo em vista a sua elevada eficiência para preservar a madeira. A presença de metais nestes preservantes exige uma destinação adequada ao fim da vida útil do poste. O presente estudo propõe a utilização do processo de pirólise como uma alternativa para a destinação final dos postes de madeira removidos da rede de distribuição de energia elétrica. A pirólise da madeira tratada com CCA promove a liberação de compostos voláteis perigosos devido à presença dos metais (Cr/Cu/As) em sua composição. Com o intuito de minimizar estas emissões, reagentes de baixo custo (a base de cálcio) podem ser utilizados durante o processo pirolítico. Neste trabalho, foram avaliados os efeitos de diferentes parâmetros de operação (temperatura, tempo de isoterma, taxa de aquecimento, razão madeira/CaO e velocidade superficial) sobre a retenção dos metais no char da madeira tratada com CCA, bem como a influência dos compostos de cálcio sobre o poder calorífico do gás combustível gerado no processo de pirólise. A caracterização da madeira tratada com CCA indicou diferenças na composição química das frações testadas (C1-alburno externo, C2-alburno interno e C3-cerne), especialmente no teor de metais. As análises para a determinação da distribuição de metais indicaram que a concentração de compostos metálicos tende à zero na linha central do poste, de forma que a elevada concentração de metais está localizada na fração externa do poste. Na análise imediata, foi observado um teor mais elevado de cinzas na fração externa da madeira. Na Espectroscopia no Infravermelho com Transformada de Fourier (FTIR) a madeira com CCA apresentou bandas similares a de uma biomassa convencional. Na Análise Termogravimétrica (TGA), observaram-se picos próximos a 276 e 354 ºC, referentes à degradação térmica das hemiceluloses e da celulose, respectivamente. A energia de ativação determinada pelo método de Kissinger foi próxima a 156 kJ·mol-1. A Ea média calculada no método de Flynn-Wall-Ozama foi de aproximadamente 153 kJ·mol-1 para C1, 182 kJ·mol-1 para C2 e 170 kJ·mol-1 para C3. Os mecanismos de reação no estado sólido verificados no método de Criado foram comandados, em sua maioria, por processos de difusão. Sob condições controladas de operação, (temperatura, tempo de residência e vazão de ar) o carbonato de cálcio (CaCO3) foi calcinado visando a obtenção de óxido de cálcio (CaO) com elevada área superficial. Os ensaios preliminares de calcinação indicaram que o CaO com maior área superficial foi obtido a 850 ºC com um tempo de residência de 5 min. Na primeira série de ensaios de pirólise verificou-se que à medida que CaO foi adicionado ao sistema, a emissão de metais e a produção de óleo foram inferiores. No segundo lote dos ensaios de pirólise, os efeitos preponderantes para a retenção dos metais no char foram a granulometria elevada das partículas, a adição de CaO e a taxa de aquecimento. Devido à adição de CaO, obteve-se menor concentração de CO2 e foi produzido um gás combustível com poder calorífico próximo a 25 MJ·Nm-3.
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Companhia Paulista de Força e Luz, CPFL
Wooden poles of the electricity distribution network are treated with preservatives to increase their shelf life. Among the various types of wood preservatives available on the market, the most used is the chromated copper arsenate (CCA), due to its high efficiency for preserving wood. The presence of metals in these preservatives requires proper disposal at the end of pole life. This study proposes the use of pyrolysis process (under controlled conditions) as an alternative to wooden poles disposal after removed from the electricity distribution network. The pyrolysis of CCA treated wood promotes the release of dangerous volatile compounds due to the presence of metals (Cr/Cu/As) in its composition. In order to minimize these emissions, low cost reagents (based on calcium) can be used during the pyrolytic process. In this work, the effect of different operating parameters (temperature, residence time, heating rate, wood/CaO ratio and superficial velocity) on the retention of metals in the char was evaluated, as well as the influence of calcium compounds on the calorific value of the fuel gas generated in the pyrolysis process. The characterization of CCA treated wood indicated differences in the chemical composition of the tested fractions (C1-sapwood, C2- outer core and C3-cord), especially in the metal content. The metals distribution analysis indicated that the concentration of metallic compounds tend to zero at the center of the pole, so the high concentration of metal is located on the outer portion. In the proximate analysis, a higher ash content on the outer portion was observed. Fourier Transform Infrared Spectroscopy (FTIR) showed bands very similar to a conventional biomass. In Thermogravimetric Analysis (TGA) peaks centered at 276 and 354 ºC were observed, relating to thermal degradation of hemicellulose and cellulose respectively. The activation energy determined by the Kissinger method was approximately 156 kJ·mol-1. The mean activation energy by the Flynn-Wall-Ozama method was 153 kJ·mol-1 for C1, 182 kJ·mol-1 for C2 and 170 kJ·mol-1 for C3. The degradation reaction mechanism determined by using the Criado is mostly controlled by diffusion processes. Under controlled operating conditions (temperature, residence time and air flow) calcium carbonate (CaCO3) was heated in order to obtain calcium oxide (CaO) with a higher surface area. Preliminary tests indicated that the calcination of CaO with greater surface area was obtained at 850 ºC with a residence time of 5 min. In the first series of pyrolysis tests, as CaO was added to the system, lesser metals emission and oil yield were observed. In the second set of pyrolysis tests, the relevant effects identified on the retention of metals was the high particle size of the wood, the addition of CaO and the heating rate. Due to the addition of CaO, the CO2 concentration was reduced and it was produced a combustible gas with a calorific value close to 25 MJ·Nm-3.

Chemical and microbiological changes at the interface between soil, and wood treated with CCA or ACA wood preservatives were investigated using a series of leaching and soil burial studies. The softwoods Scots pine (Pinus sylvestris, L.), Sitka spruce (Picea sitchensis, Carr) and the hardwood lime (Tilia vulgaris, Hayne) were used exclusively. Copper losses from both types of preservative treated wood were negligible, though adjacent soil copper concentrations significantly increased. These copper accumulations were associated with a reduction in dehydrogenase activity around the preservative treated material compared with levels around the untreated blocks, though activity around the treated wood was rarely less than background levels. Relatively large arsenic concentrations accumulated around the most heavily ACA-treated blocks, and were associated with a further reduction in activity of the soil microflora. The wood species also affected the microbial activity in adjacent soil; activity around all lime blocks was generally greater than microbial activity around the softwoods. Treatment of wood with ammonia or ACA solutions increased the wood nitrogen contents. Some of this nitrogen was readily water soluble, though its rapid diffusion into adjacent soil had no effect on microbial activity in this area. Water insoluble nitrogen was also retained within these blocks; this was shown to increase the rate of microbial colonisation and decay of the wood and was also associated with an increased toxic value of copper. Microbial activity was measured in all decaying wood blocks. This activity was influenced by the wood species, and treatment, as were the microbial colonisation and decay rates. The experimental conditions employed were designed to promote soft rot, rather than other forms of wood decay. Activity was greater in the outer wood surface of the buried blocks than in the inner wood, reflecting the surface nature of soft rot decay. Pre-burial leaching reduced the subsequent moisture uptake and increased the durability of CCA-treated wood during soil burial, though untreated wood was unaffected. However, similar rates of microbial decay of untreated wood blocks occurred over a range of different wood moisture contents. The implications of the findings on the relative performances of untreated, ammonia, CCA and ACA-treated wood in soil contact are discussed.

A preservação química visa proteger a madeira contra quaisquer ações deterioradoras, sejam elas consequências de fenômenos físico-químicos, como a ação do intemperismo, ou de fenômenos biológicos, como os organismos xilófagos. No Brasil, os preservativos mais utilizados nas usinas de preservação são o Arseniato de Cobre Cromatado (CCA) e o Borato de Cobre Cromatado (CCB). Ambos são aplicados na madeira através do processo de vácuo-pressão, método que em tese poderia aumentar a quantidade de defeitos superficiais e diminuir os valores das propriedades físico-mecânicas das madeiras. Atualmente, em decorrência da disponibilização no mercado (devida à implantação de áreas certificadas no Brasil) de espécies de madeira de média a baixa densidade, a questão da necessidade da preservação contra a demanda biológica se constitui em aspecto de fundamental importância para que se garantam as alternativas de oferta desse material para a construção de estruturas, cuja durabilidade seja equivalente à da madeira de espécies de uso consagrado, como Jatobá, Sucupira, Garapa e Itaúba, por exemplo. Neste contexto, o presente trabalho teve como objetivo investigar a influência dos tratamentos com os preservativos CCA e CCB nas propriedades físico-mecânicas das seguintes espécies de madeiras tropicais brasileiras: Simarouba amara (C20), Cedrelinga catenaeformis (C30) e Erisma uncinatum Warm (C40), escolhidas na tentativa de abranger as três classes de resistência mais baixas, de acordo com o que prescreve a ABNT NBR 7190:1997. Foi realizada a caracterização completa de cada espécie nos três tipos de tratamento (Sem tratamento – Ref; CCA; CCB) para posterior aplicação do teste de comparações múltiplas de Tukey, avaliado ao nível de 5% de significância. Para avaliar o comportamento dos preservativos a nível celular, foram geradas fotomicrografias por Microscopia Eletrônica de Varredura (MEV) e seus respectivos espectros de EDS. Os resultados obtidos mostraram que ambos os tratamentos químicos não afetaram significativamente os valores das propriedades físico-mecânicas das espécies estudadas.
The chemical preservation aims to protect the wood against any deteriorating actions, be they consequences of physical-chemical phenomena, such as weathering, or biological phenomena, such as xylophagous organisms. In Brazil, the most used preservatives in the preservation plants are Chromated Copper Arsenate (CCA) and Chromated Copper Borate (CCB). Both are applied to the wood through the vacuum-pressure process, which in theory could increase the amount of surface defects and decrease the values of the physical-mechanical properties of the wood. Currently, due to the availability in the market (due to the implantation of certified areas in Brazil) of medium to low density wood species, the question of the need for preservation against biological demand is an aspect of fundamental importance to ensure the alternatives of supply of this material for the construction of structures, whose durability is equivalent to the wood of species of consecrated use, such as Jatobá, Sucupira, Garapa and Itaúba, for example In this context, the present work had as objective to investigate the influence of the treatments with the preservatives CCA and CCB on physical-mechanical properties of the following species of Brazilian tropical woods: Simarouba amara (C20), Cedrelinga catenaeformis (C30) e Erisma uncinatum Warm (C40), chosen in an attempt to cover the three lower resistance classes, according to what ABNT NBR 7190:1997 prescribes. The complete characterization of each species in the three types of treatments (No treatment - Ref: CCA; CCB) was performed for the subsequent application of the Tukey\'s multiple comparison test, evaluated at the 5% level of significance. To evaluate the behavior of the preservatives at the cellular level, photomicrographs were generated by Scanning Electron Microscopy (SEM) and their respective EDS spectra. The results obtained showed that both chemical treatments did not affect significantly the values of the physical-mechanical properties of the studied species.

Chromated copper arsenate (CCA) has been the most commonly used wood preservative in the UK; up until its partial ban in 2004. The preservative prolongs the service life of wood by 20-50 years by making it resistant to biological attack. As such, in-service CCA treated wood is expected to be a major component of the UK wood waste stream in the future. Concerns over the impact of the chemical constituents of this treatment on both the environment and human health have prompted the introduction of legislation to ensure that such waste is disposed of safely in Hazardous Waste Landfills. Despite this, studies have shown that this waste can still enter into the landscape mulch market due to inadequate detection methods and increasing societal pressures to recycle. A series of laboratory and field-based simulations were used to quantify leaching of copper, chromium and arsenic from CCA-treated wood waste mulch and evaluate the factors involved in promoting leaching. The distribution and behaviour of the metals in the soil column and leachate were also assessed. The samples generated in the study were analysed for a range of physico-chemical measurements, elemental and speciation concentrations. Results show that arsenic, chromium and copper leaches from CCA waste wood; at times to levels exceeding regulatory thresholds by two to three orders of magnitude. Furthermore, the more toxic and mobile species of arsenic (As III) and chromium (Cr VI) were detected in both soil and leachate samples. A mass balance was produced which demonstrated that CCA wood tends to leach on initial exposure to a leachant and also during weathering of the wood. When in contact with soil, metal(loid) transport is reduced due to complexation reactions. With higher water application or where the adsorption capacity of the soil is exceeded, the metal(loid)s are transported through the soil column as leachate. Overall, there was a loss of metal(loid)s from the system that could be due to loss of water, volatilisation of arsenic and plant uptake. Due to the toxicity and concentration levels of the leached elements identified in the current study, it is apparent that adverse environmental and human health impacts may result from direct and indirect exposure to the environmental media.

The impact of two formulations of chromated copper arsenate (CCA) wood preservatives (Celcure AO and Tanalith C33 10) on a range of marine organisms was assessedin both laboratory and field investigations. As part of an EU project, a long-term field investigation was carried out exposing test panels of Scots pine treated to 12,24 and 48 kgm -3 CCA and untreated controls at seven coastal sites (Portsmouth, UK; Kristineberg, Sweden; La Tremblade (2 sites), France; Ria Formosa, Portugal; Sagres, Portugal; Athens, Greece). Inspections were made at 6,12 and 18 months after submergence and the fouling communities on CCA-treated and untreated panels were assessed both quantitatively and qualitatively. Over the course of the field trial patterns of fouling that were common at several of the sites were recorded. In the majority of cases there were no significant differences in species abundance, species diversity, community organic biomass and total dry weight of fouling organisms on CCA-treated versus untreated panels. However, a number of species were recorded in significantly higher numbers on CCA-treated panels compared to untreated panels. The extent and type of microbial degradation of these panels was also assessed. Sections from the panels exposed for periods of 6,12 and 18 months were examined by light microscopy and the depth of penetration by soft rot fungi and tunnelling and erosion bacteria was measured. Attack was found to be heavy in untreated wood, but absent or very superficial in CCA-treated wood. The fungal flora was also recorded after 6,12 and 18 months exposure following incubation of panels. Fungal diversity on untreated wood was high, whereas on CCA-treated wood fungi were either absent, or a low diversity present. The surfaces of untreated panels were notably softer as a result of microbial and marine borer attack. Scanning electron microscope studies revealed that the rate of biofilm formation on the surfaces of CCA-treated panels (12,24 and 48 kgm -3 CCA) was marginally faster than on the surface of untreated panels over a4 week exposure period in the sea at the Portsmouth exposure site. After 4 weeks of exposure no differences in biofilm composition were detectable between different panel treatments. Algal fouling was monitored on CCA-treated and untreated Scots pine panels after submergence at the exposure site at Portsmouth, UK for a period of 4 weeks. In the majority of cases there were no significant differences in the abundance of each algal species on CCA-treated or untreated panels. Two species of algae were recorded in significantly lower abundance on CCA-treated panels compared to untreated panels, suggesting that these species were sensitive to leached preservative from the surfaces of the treated panels. The impact of CCA-preservatives on invertebrate fouling was also monitored over the initial 4 weeks of submergence. Scots pine panels treated to 2,4,6,12,24 and 48 kgm -3 (Celcure AO and Tanalith C3310), and untreated controls were exposed at a brackish water millpond, Emsworth, UK. Settlement densities of 3 species of calcareous invertebrates were measured. Densities of the serpulid Ficopomatus enigmaticus significantly increased with increasing CCA loading; numbers of the two species of barnacle (Elminius modestus and Balanus crenatus) were also higher on CCA-treated panels than on untreated panels but these differences were often not significant. A laboratory leaching trial combining a static and a flowing seawater system was carried out to measure the leaching rate of copper, chromium and arsenic from the surface of Scots pine panels treated to 3,6,12,24 and 48 kgm-3 CCA. Losses of chromium and arsenic over the 10 week trial were very low, whereas losses of copper were much higher. Copper losses from freshly treated panels were highest, but rapidly fell to much lower levels after exposure in flowing seawater. Laboratory bioassays were carried out to test the toxicity of leachates from CCA-treated wood, or their toxic components. Tests on the thraustochytrid, Schizochytrium aggregatum, examined the effects of copper ions on mortality of sporangia and motility and viability of zoospores. A very high tolerance to copper ions was recorded in both instances. Experiments exposing spores/zygotes of two species of marine algae found that concentrated leachates from CCA-treated wood inhibited germination of Fucus serratus zygotes but only reduced the percentage germination of Undaria pinnatifida spores. All of the bioassays used produced rapid results. Data suggests that CCA-treated wood is not toxic to non-target marine fouling organisms. Preferences to settle on CCA-treated wood over untreated wood by certain marine fouling organisms may be due to differences in the surface properties of the wood (surface energy, biofilm formation) influencing choice of settlement sites by fouling propagules. Differences manifested at this initial stage of the fouling process may be reflected in the mature fouling community.

This thesis is concerned with the management of wood waste generated after demolition of a typical 33 year old coke quenching tower from an integrated steelworks. Wood in the coke quenching tower was treated with traditional waterborne preservative, Copper-Chromium-Arsenic (CCA). Due to the growing environmental concern, changes were introduced in the legislation governing the disposal of waste. Hence, the aim of the thesis was to perform a waste management study by investigating CCA treated wood waste and to develop a waste disposal technique. During the characterisation of the wood waste, elemental analysis was performed to confirm CCA concentration remaining in the treated wood waste. Concentration of CCA elements ranged from 300mg/kg to 10,000mg/kg. The concentration reduced with increase in the years of service life of the treated wood. Leaching tests according to British Standards were performed for different durations from 1 hour to 1 month to determine the leaching behaviour exhibited by the wood. Standard and customised sampling procedures were carried out for leaching tests to study and simulate the loss of CCA from the treated wood during a quenching process. These tests provided a leaching pattern that the loss of CCA follows a trend of As > Cu > Cr which was in agreement with the final concentrations of the quenching tower wood, such that chromium was most resistant to leaching and arsenic was most susceptible to leach. Correlations and linear equations were established between the arsenic-chromium and arsenic-copper leach concentrations. Equations were developed to help in predicting the ratio of leach ability of the CCA elements with respect to each other. It was also found that the wood from the tower contained a substantial amount of iron which was further investigated. The growth ring analysis showed that iron was mainly deposited on the wood surface. The prime sources of iron were identified to be kish, an air borne particulate matter found in steelworks environment as well as coke and coke ash. Leaching studies performed to determine the leachability of iron showed that there was a potential for iron to restrict the mobility of CCA elements in soil. A novel three-step chemical extraction method was developed after analysing the sequential analysis performed with different chemical reagents and leaching behaviour of the CCA wood waste. Step one used sodium hydroxide (NaOH) to break down the wood structure by lignin depolymerisation. The use of NaOH provided alkaline conditions and facilitated the process of lignin depolymerisation mainly to release arsenic as water soluble compounds. This was followed by ammonium chloride (NH4Cl) for release of copper, due to the high affinity of ammonium group to form complexes with copper. Hydrogen peroxide (H2O2) was used as a strong oxidising agent and primarily to release the chromium by forming chromium complexes which are readily soluble in water. The effect of the pH, temperature, concentration and order of the reagent to be used were studied. Therefore, CCA wood was subjected to the three-step process, where the order was designed as NaOH followed by NH4Cl and then H2O2 for 1 hour at 100oC with 1 M, 2 M and 2 M concentration respectively. 98 %, 89 % and 96 % for arsenic, chromium and copper respectively was the extraction percentage achieved by the three step process. The three elements were obtained in a water solution and a dry wood residue. The process showed the potential in an alkaline extraction method with high extraction levels in three hours. The process also provided wood residue with possible uses in paper and pulp industry. In order to complete the treatment method the CCA elements present in water solution obtained after the three-step extraction process were required to be precipitated. The CCA elements present in water soluble state were precipitated by using an electrocoagulation process. Various parameters were analysed including type of electrodes, a suitable pH range, current, and concentration of the solution to optimise the whole process. The pH of the solution played a vital role in the precipitation of the elements. The pH value was adjusted to 4 in order to achieve the maximum removal potential. The mild steel electrodes were selected over the aluminium. The iron ions released from the mild steel electrodes formed insoluble complexes with the CCA elements in the solution as compared to the soluble aluminium ions. The final process was optimised to 15 minutes of duration using mild steel electrodes and 0.8 A current at room temperature. The solution used for the electrocoagulation was diluted to the factor of 1:5. The full process precipitated about 99 % of CCA elements from water which was filtered and analysed. Overall, the thesis provided in-depth characterisation of the CCA treated wood waste arising from a steelworks environment. The leaching behaviour and the presence of iron were studied to provide a better understanding for the disposal of such wastes. A chemical extraction method followed by the electrocoagulation for the disposal of CCA treated wood waste provided a foundation for a scaled up treatment method and final disposal of such wastes.

Professional builders (PRO's) and do-it-yourself (DIY) households throughout the U.S. were surveyed individually to assess their overall knowledge/awareness, product and service attribute preference and the general product quality and risk perceptions of CCA pressure treated lumber products. Primary data were acquired via two separate nationwide mail surveys; one included 3,361 PRO's, the other was administered to 3,224 households. Findings indicate that each of these retail customer groups is comprised of distinct subsegments that may be distinguished in various ways. These meaningful PRO segmentation strategies emerged from analysis of 543 PRO respondents portraying treated lumber customers according to the following: (1) geographic region as characterized by product and service attribute preferences, opinions, knowledge and demographics, (2) quality perceptions in terms of the relationship between benefits sought and product quality perception opinions and (3) physical risk or safety perceptions based on a risk personality type as delineated further according to three sets of psychographic predictor variable sets. The 491 responding DIY'ers were segmented according to risk perception orientation similarly to the builders. In addition, the DIY'er was profiled with regional breakdowns for treated lumber usage, applications and purchase intent, the husband/wife involvement in treated lumber buying decisions, knowledge, and product and service attribute importance. Consumer knowledge and awareness of pressure treated lumber products, in general, is very low. Only one-third of PRO's and 21% of DIY'ers could recall, unaided, at least one brand of treated lumber. Moreover, approximately one-third of all PRO and DIY respondents are knowledgeable about the preservative chemicals and a mere 38% of the 436 PRO respondents and 23% of the DIY respondents who have used treated lumber products from 1985-1987 could successfully identify the correct response from a multiple choice question which described the contents of Consumer Information Sheets (CIS's). Primarily through reading materials, Permanent Wood Foundations (PWF's) are well known among builders with 70% aware. However, only one-fourth of DIY'ers have ever heard of PWF systems.
Ph. D.

A durabilidade da madeira preservada quando em contato direto com o solo, é determinada, principalmente, pela concentração do preservante na madeira, usualmente definida como retenção. Dentre os diversos produtos usados na preservação da madeira, a literatura especializada é concordante ao afirmar que o CCA (arsenato de cobre cromatado) é um dos mais eficientes, com citações de durabilidade acima de 40 anos. Contudo, também é citada a perda do produto ao longo do tempo, a qual poderia comprometer sua eficiência. Assim o presente trabalho teve como objetivo quantificar a retenção atual de CCA tipo A em estacas de Pinus, após 21 anos de exposição em campo de apodrecimento, buscando relacionar o nível de retenção com a possível perda de produto e com a durabilidade da madeira. O material para ensaio foi coletado de um campo de apodrecimento com estacas (Padrão IUFRO); quantificando-se a retenção atual através da técnica de espectrofotometria de absorção atômica e comparando-se os resultados com a retenção inicial. Foi possível comprovar a perda de CCA-A na madeira tratada, a qual está diretamente relacionada com o nível de retenção inicial. Dentre oscomponentes do preservante, as maiores perdas foram observadas para o Cu, e as menores para o Cr; levando ao desbalanceamento entre os componentes do produto (CCA-A) que permanece na madeira. Todavia, a redução observada na retenção do CCA-A, até o momento, não afetou a durabilidade da madeira preservada.
The durability of treated wood in direct ground contact is mainly determined, by the concentration of preservative in wood, usually defined as retention. Among the products used to preserve wood, specialized literature aggress about CCA (chromated copper arsenate) as one of the most efficients, with citations of durability above 40 years. However, product loss along exposure time is also noticed, which could compromise its efficiency. This research has as objective, to quantify the current retention of CCA type A in Pinus stakes, after 21 years of exposure in field test, trying to relate the level of retention to the possible product loss and to wood durability . The material on trial was collected from a stake field test (IUFRO Standard); in order to quantify the current retention through spectroscopy atomic absorption technique and to compare the results with the initial retention. It was possible to prove the CCA-A loss in the treated wood, which is directly related to the level of initial retention. From individual preservative components, copper (CuO), showed the biggest loss, while chromium (CrO3) showed the lesser one. As a result, the remanaing CCA-A in the lumber turned unbalanced. However, the reduction observed in the retention of the CCA-A, until this moment, did not affect the durability of preserved wood.

Weathered waterborne treated wood is believed to behave differently than new wood during service regarding the loss of its metallic-based preservatives. Also, weathered preserved wood should be separated from the unpreserved wood upon recycle. The first objective of this dissertation was to evaluate losses from weathered CCA-treated wood samples at different retention levels under normal field conditions and to compare leaching to new ACQ (as alternative to CCA). Results showed that arsenic leached at a higher rate than chromium and copper in all CCA treated wood samples, while copper leached the highest from the ACQ sample. Overall results suggest that the leaching rate of metals on a percent basis from in-service pressure treated wood may increase as the wood weathers; however due to lower retention levels of the metals in the wood as it ages the yearly mass of metals lost would be at similar or at lower quantities in comparison to new treated wood. The second objective was to evaluate the use of automated X-ray fluorescence (XRF) systems for identifying and removing As-based and Cu-based treated wood within the recovered wood waste stream. A full-scale online automated XRF-detection, conveyance and diversion system was used for experimentation. At the different applied feeding rates and belt speeds, online sorting efficiencies of waste wood by XRF technology were high (>70% for both treated wood and untreated wood). The incorrectly diverted pieces of wood were attributed to deficiencies in the wood conveyance systems and not to deficiencies in the XRF-based detection. Online sorting was shown to sort wood which would meet the residential soil cleanup target levels in Florida when an infeed is composed of 5% of treated wood pieces. Comparisons with other sorting methods show that XRF technology can potentially fulfill the need for cost-effective processing at large wood recycling facilities (> 30 tons per day). Management of weathered CCA-preserved wood, due to its continuity of leaching metals and the need to remove it upon the recycle of wood, will likely continue until complete banning and removal from the environment, a process that may extend up to the next century.

Includes abstract.
Includes bibliographical references.
In developing countries, energy poverty remains a challenge, impacting on the environment, health, security and well-being of an estimated 3 billion people. Fuel wood remains an important but environmentally problematic fuel in this context. The urban poor are known to make use not only of harvested but also of waste timber. Prior studies in Cape Town indicated substantial uses of fuel wood by informal communities for thermal requirements, such as cooking and heating by both households and informal and formal caterers.This dissertation therefore aims to determine whether, and how, informal urban caterers and their clients are exposed to toxicity risks arising from Chromium, Copper and Arsenic in their fuel-wood.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Wood poles used in electrical lines were from Eucalyptus species. These poles should present adequate mechanical characteristics in order to ensure the security and structure of electrical lines. Wood poles should be treated with products able to protect the wood against insects and fungus to increase service life. Taking these into account, this study aims to evaluate mechanical properties of wood poles and qualify preservative treatment used in the wood poles. Mechanical evaluation of wood poles was performed through nondestructive tests of ultrasonic wave propagation and destructive tests according to NBR 6231 (ABNT, 1980) in order to establish a method to estimate mechanical properties through nondestructive tests. Preservative treatments through full-cell method were carried out for 60, 90 and 120 minutes with pressure of 10 and 12 kgf/cm2 using a CCA-C preservative solution. Tests of penetration and retention of the solution were performed to evaluating the preservative treatments. Chemical analysis of wood was done through extractives content, Klason lignin content and infrared spectroscopy (ATR-IR). The evaluation of mechanical properties showed not significant correlation coefficients between MOEeng. and dynamic modulus of elasticity, proving the inefficiency of nondestructive method in this study. The results of preservative treatments showed that CCA-C penetration on wood was deep and irregular in 50-70% of poles for both species. On the other hand, retention did not present the minimum value required by NBR 8456 (ABNT, 1984). This analysis showed that higher pressure and time of treatment, higher is CCA-C retention. Wood from both species presented similar results for extractives content and Klason lignin content. Infrared spectroscopy (ATR-IR) technique did not show a efficiency to predict the chemical modification in treated wood.
Os postes de madeira que são utilizados nas redes elétricas no Brasil são oriundos, na sua grande maioria, de madeira da espécie Eucalyptus. Esses postes devem apresentar características mecânicas adequadas garantindo segurança a estrutura das redes. Para garantir uma maior vida útil, a madeira dos postes deve receber tratamento preservativo com soluções capazes de resistir ataques de insetos e fungos degradadores da madeira. Sendo assim, o presente estudo tem por objetivo avaliar as propriedades mecânicas e qualificar o tratamento preservativo utilizado nos postes de madeira. A avaliação das propriedades mecânicas dos postes de madeira foi realizada por meio de testes não destrutivos de propagação de ondas de ultrassom e testes mecânicos destrutivos conforme a norma NBR 6231 (ABNT, 1980), a fim de estabelecer uma metodologia, com intuito de estimar as propriedades mecânicas da madeira por meio de ensaio não destrutivos. Também foram realizados tratamentos preservativos por meio do processo de célula cheia em períodos de 60, 90 e 120 minutos com pressão de 10 e 12 kgf/cm², utilizando a solução preservante Arseniato de Cobre Cromatado tipo C (CCA-C). Na avaliação do tratamento preservativo da madeira, foram realizados testes de penetração e retenção da solução preservativa. Ainda, realizaram-se análises químicas da madeira, por meio da quantificação de teor de extrativos, teor de lignina Klason e análises qualitativas com ensaios de espectroscopia no infravermelho (ATR-IR). Na avaliação das propriedades mecânicas dos postes de madeira, observaram-se coeficientes de correlação não significativos ente MOEeng. e módulo de elasticidade dinâmico, evidenciando a ineficiência do método não destrutivo no presente estudo. Os resultados para os tratamentos preservativos mostraram que a penetração do CCA-C na madeira foi profunda e irregular em 50 a 70% dos postes de ambas as espécies. Já as análises de retenção, mostraram que a maioria dos postes de madeira não apresentaram as retenções mínimas exigidas pela norma NBR 8456 (ABNT, 1984). Ainda, essas análises mostraram que quanto maior a pressão aplicada e maior o tempo de tratamento, melhores são os resultados para a retenção do CCA-C. As madeiras de ambas as espécies apresentaram resultados semelhantes tanto para o teor de extrativos quanto para o teor de lignina Klason. Já a técnica de espectroscopia no infravermelho (ATR-IR) não apresentou eficiência quanto à predição de modificações químicas na madeira tratada.

End products of society (e.g. sewage sludge and incineration ashes) can be used as indicators of the use of chemicals in consumer goods. Through upstream work the sources of substances released from goods may be identified before the emissions reach the end products. This thesis is a result of five studies, of which four were conducted using substance flow analyses (SFA) for silver (Ag), bismuth (Bi) and copper (Cu) reaching sewage sludge. The fifth is an SFA that explores the implications of the presence of As (from CCA-treated wood) in ashes. These studies helped fulfil the specific and overall aims of the thesis; to contribute to the general knowledge on diffuse emissions reflected in end products, by examining emissions of some heavy metals from various societal goods and the implications for end products, in this case sewage sludge and, to some extent, ashes. The results from the studies, of which four had Stockholm as a study object, show the urban flows and accumulated amounts (stocks) of the heavy metals. The largest sources of the metals Ag, Bi and Cu in sewage sludge were identified to be textiles (Ag), cosmetics (Bi) and brake linings (Cu). For As (in CCA-treated wood) and Cu updated SFAs were performed and compared with earlier studies in order to follow the development and changes in flows over time. The current use of the heavy metals studied can also be seen as a loss of resources, and as the metals should ideally be recovered as a part of a circular economy, urban and landfill mining as well as recycling are alternatives that need further exploring. The legislation of chemicals in consumer goods was identified as an important step in handling corresponding diffuse emissions.

Chromated copper arsenate (CCA), type C, was largely used as a wood preservative due to its exceptional fungicidal and insecticidal properties. Although this treatment was prohibited for residential purposes in Canada and in the United-States of America, concerns about CCA-treated wood focus on the possible threat on human health and the contamination of the environment, through the leaching of metals from existing structures. The objectives of this thesis are (1) to assess the effects of metals leached from CCA- and ACQ-treated wood on the survival, the growth and the reproductive success of the earthworm Eisenia fetida (Annelida, Oligochaeta), and (2) to evaluate if annetocin, a neuropeptide linked to reproduction, could be used as a biomarker of ecotoxicological responses of the worm E. fetida when exposed to metals from the CCA treatment. Ecotoxicological tests with E. fetida were carried out according to the protocol ISO-11268-2. (Abstract shortened by UMI.)

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O setor madeireiro tem crescido nos últimos anos no Brasil, visto que o país possui vastas áreas com florestas de reflorestamento. Entretanto, com o passar dos anos, tem crescido a consciência de uma melhor utilização das matérias-primas, inclusive da madeira. Neste contexto, surgem os painéis à base de madeira, os quais utilizam melhor as toras, que podem ser de diferentes dimensões. Dentre estes painéis, destaca-se o compensado laminado, que é um painel produzido com um número ímpar de lâminas de madeira, dispostas perpendicularmente umas às outras com relação a direção da grã. Este painel possui ampla utilização, principalmente na indústria moveleira e na construção civil, podendo ser utilizado em construções do tipo wood frame. Além disso, o compensado necessita passar por algum processo de tratamento contra o ataque de fungos, insetos e intempéries. Assim, este estudo teve o objetivo de analisar a influência de tratamentos preservativos nas propriedades físicas e mecânicas do compensado laminado de Pinus taeda. Para isso, foi realizada a termorretificação, com três diferentes temperaturas (160°C, 180°C e 200°C) e o tratamento químico com CCA. Foram realizados os tratamentos das lâminas antes da produção do compensado e os tratamentos dos painéis já produzidos, sem prévio tratamento das lâminas, com o intuito de avaliar qual forma de tratamento é a mais adequada. Foram realizadas as análises de teor de extrativos totais, molhabilidade das lâminas, microscopia eletrônica de varredura e testes físicos e mecânicos. Os resultados obtidos mostraram que os tratamentos de termorretificação e o tratamento com CCA melhoraram a estabilidade dimensional do painel compensado, devido às alterações químicas ocorridas na madeira. Além disso, ambos os tratamentos diminuíram a resistência mecânica à flexão estática e a qualidade de colagem. Entretanto, todos os tratamentos continuaram a atender as especificações mínimas de órgãos normativos. Com base em todas as análises concluiu-se que a termorretificação do painel a 200°C mostrou-se mais adequada.
The forestry sector has grown recently in Brazil, since the country has vast reforestation fields. However, over the years, there has been growing the consciousness of a better use of raw materials, including wood. In this context arise the wood based panels, which make better use of logs, which may be of different dimensions. Among these panels is highlighted the plywood, which is a panel produced with an odd number of wood veneers arranged perpendicularly to each other with respect to the grain direction. This panel has wide application, especially in the furniture industry and in construction and can be used in wood frame type construction. Besides that, the plywood needs to undergo some treatment process against the attack of fungi, insects and weatherproof. Thus, this study aims to analyze the influence of preservative treatments on physical and mechanical properties of Pinus taeda plywood. To this were performed the heat treatment with three different temperatures (160 °, 180 ° C and 200 ° C) and chemical treatment with CCA. It was carried out the veneers treatments before the production of plywood and the panel treatment, without prior veneers treatment, in order to assess which form of treatment is most appropriate. The analyzes of extractive content, veneers wettability, scanning electron microscopy and physical and mechanical tests were performed. The results showed that the heat treatment and CCA treatment improved the dimensional stability of the plywood due to chemical changes in the wood. In addition, both treatments decreased mechanical strength in static bending and bonding quality. However, all treatments continued to meet the minimum specifications of specialized organs. Based on all the analyzes it was concluded that the heat treatment of the panel at 200°C was more adequate.

O Brasil produz cerca de 2,2 milhões de metros cúbicos de madeira preservada para atender à demanda anual nos setores de transporte ferroviário, elétrico, rural e de construção civil. As espécies de madeiras mais usados são do eucalipto (Eucalyptus sp.) e pinus (Pinus sp.). A madeira preservada, utilizada para postes, dormentes, mourões e nas construções em madeira, deve estar em conformidade com as especificações exigidas pelas normas brasileiras quanto ao seu tratamento preservativo. No Brasil, os preservativos de madeira mais utilizados e regulamentados são CCA (arseniato de cobre cromatado) e o CCB (sal de cobre cromo e boro). As técnicas analíticas como espectrometria de absorção atómica de chama (FAAS) e espectrometria de emissão de plasma acoplado (ICPOES) e espectrometria de fluorescência de raios x (XRFS) são utilizadas para a avaliação desses processos. Neste trabalho, as amostras de madeira foram obtidas de árvores de eucalipto (Eucalyptus sp.), provenientes de áreas de plantação do estado de Minas Gerais, Brasil. Amostras de madeira de eucalipto foram submetidas a diferentes concentrações de solução de CCA, sob pressão, atingindo retenções de 3,9; 6,7; 9,1; 12,4 e 14,0 kg de CCA por m-³ de alburno. A partir dos blocos tratados foram obtidos amostras em forma de cilindros e serragem. A determinação de cobre, cromo e arsênio foi realizada pela espectrometria de fluorescência de raios X de energia dispersiva (EDXRF), espectrometria de fluorescência de raios X portátil (PXRF), FAAS e IAAN. Neste trabalho, foram avaliados métodos de análise, sensibilidade e precisão, exatidão das técnicas analíticas relacionadas.
Brazil produces around 2.2 millions of cubic meters of treated wood to meet the annual demand of railway, electric, rural and construction sectors. The most used wood species are eucalyptus (Eucalyptus ssp.) and pine (Pinus ssp.).The treated woods used for poles, sleepers, fence posts and plywoods should be according to Brazilian norms requirements. The most usual wood preservative products used in Brazil are CCA (chromated copper arsenate) and CCB (copper chromium and boron salt). The analytical methods, such as flame atomic absorption spectrometry (FAAS), plasma inductively coupled optical emission spectrometry (ICPOES) and X-ray fluorescence spectrometry (XRFS) have been used for the analytical control of those treatment processes. In this work, the eucalyptus trees (Eucalyptus ssp) samples was obtained from Minas Gerais State, Brazil, cut plantation areas. Under pressure, eucalyptus wood samples were submitted to different concentration of CCA solution reaching 3.9, 6.7, 9.1, 12.4 and 14.0 kg of CCA by m-³ sapwood retentions. Samples in cylinders and sawdust forms were obtained from treated wood samples. Copper, chromium and arsenic determination was performed using the energy dispersive X-ray fluorescence spectrometry (EDXRFS), portable X-ray fluorescence spectrometry (PXRFS), flame atomic absorption spectrometry (FAAS) and instrumental neutron activation analysis. In this work, the method of analysis, sensitivity, precision and accuracy performances of the related techniques were outlined.

O CCB (sais de cromo, cobre e boro) surgiu como alternativa ao CCA, apresentando menor toxicidade ao meio ambiente e em muitos casos conferindo excelentes propriedades mecânicas à madeira. Estima-se que, de 15 a 20% (aproximadamente 240 mil \'M POT.3\'/ano) da madeira tratada no Brasil atualmente sejam resíduos, considerando-se apenas aqueles provenientes do seu beneficiamento, desconsiderando os produtos pós-consumo. Por outro lado, o Brasil possui excelentes condições para a produção dos painéis aglomerados, com produção estimada atualmente em 2,5 milhões \'M POT.3\'/ano. Observando o crescimento do mercado de painéis à base de madeira e a constante busca por produtos sustentáveis, este trabalho teve como objetivo principal a análise da viabilidade de produção de chapas de partículas, empregando-se resíduos de Pinus sp tratado com preservante CCB e resina poliuretana à base de mamona. Foram variados parâmetros de produção para obtenção de melhores condições de processo, sendo estes: quantidade de partículas, com 1300g e 1400g; teor de adesivo, de 12% e 15% e; tempo de prensagem, de 10 e 12 minutos. Caracterizaram-se as partículas empregadas quanto as suas propriedades físicas e morfológicas, além da análise dos painéis quanto às características físico-mecânicas, segundo NBR 14810-3 (2006), submetendo-se também amostras com melhores desempenhos ao Envelhecimento Artificial Acelerado, conforme ASTM G155 (1999) e análise da morfologia, por meio de ensaios de Microscopia Eletrônica de Varredura (MEV) e Porosimetria por Intrusão de Mercúrio. Determinou-se também a retenção dos ingredientes ativos de preservante nas partículas e chapas, para avaliação de possíveis perdas na retenção devido ao processo de prensagem. Os resultados apontaram para excelentes propriedades físicas e mecânicas das chapas de partículas, em alguns casos em média 50% superiores ao estipulado pela norma brasileira em questão e superiores aos requisitos das normas internacionais. Assim, ficou evidenciada a viabilidade de produção dos painéis com os insumos estudados bem como seu potencial de emprego para as finalidades compatíveis com produtos desta natureza.
CCB (chromium, copper and boron sales) has risen as an alternative to CCA, because of its toxicity level and, in several cases, conferring high properties to treated wood. In Brazil, some evaluations show that nearly 15 to 20% (something like 240.000 \'M POT.3\'/year) of this wood are residues generated by processing phases, without taking in account pos-used product. Besides, Brazilian particleboard industry produces 2.500.000 \'M POT.3\'/year. Observing wood based panels demand improvement and sustainable products search, the aim of this work is to confirm feasibility of producing particleboards with CCB treated Pinus sp residues and polyurethane resin based on castor oil. Different production parameters were employed in order to optimize process conditions, like: particles (1300g and 1400g); adhesive percentage (12 and 15%); pressure time (10 and 12 minutes). Particles were characterized by their physical and morphological properties. Panels\' performance was determined based on their physical and mechanical properties, as prescript in Brazilian Code NBR 14810-3 (2006). Special specimens were used in order to evaluate influence of accelerated aging as proposed in ASTM G155 (1999). Morphological aspects were analyzed by Scanning Electron Microscopy (SEM) and Mercury Intrusion Porosimetry. Active ingredients retention was also determined to establish casual lost after producing process. Results show excellent physical and mechanical properties, some of them 50% higher than NBR14810-3 and international codes requirements. Feasibility of producing particleboards like those studied was demonstrated as well as potential of their employing in same uses of commercial boards.

Les déchets de bois traités représentent 27% du gisement des déchets dangereux en France. Ces déchets sont incinérés dans des installations classées pour la protection de l'environnement (ICPE). Néanmoins, leur incinération nécessite des équipements robustes et coûteux pour le lavage des gaz et des fumées toxiques. Dans ce contexte, le présent travail a pour objectif d'élaborer et de mette en oeuvre d'autres voies de valorisation énergétique des déchets de bois traités par des procédés thermochimiques. Pour cela, les procédés de pyrolyse et d'hydroliquéfaction ont été mis en oeuvre principalement pour la valorisation énergétique des déchets de bois traités aux sels de CCB (cuivre-chrome-bore) qui représentent 8750 tonnes/an en France. Le bois imprégné de sels de CCB dans nos laboratoires conformément au traitement industriel, a été étudié afin de maîtriser le bilan des métaux dans les différents produits de pyrolyse et d'hydroliquéfaction. Une étude préliminaire de son comportement thermique a été menée par analyse thermogravimétrique dans le but de déterminer l'intervalle de température effectif à sa dégradation massique. Dans cet intervalle de température, les paramètres expérimentaux de pyrolyse lente ont été optimisés pour piéger les métaux dans le charbon. Par la suite, une étude paramétrique par la méthode des plans d'expérience a été réalisée pour la conversion du charbon en bio-huile. De plus, l'optimisation de l'hydroliquéfaction pour la conversion du bois traité en bio-huile a été effectuée. Les résultats montrent que les métaux initialement présents dans le bois traité sont répartis entre la bio-huile et le coke quelque soit la voie de valorisation énergétique empruntée (hydroliquéfaction/pyrolyse+hydroliquéfaction). Cependant la bio-huile présente des caractéristiques proches de celles des biodiesels. L'utilisation de catalyseur au cours de l'hydroliquéfaction du charbon de pyrolyse améliore non seulement la qualité de la bio-huile mais aussi le bilan d'énergie sur le procédé.

Dissertação apresentada como requisito parcial para obtenção do grau de Mestre em Ciência e Sistemas de Informação Geográfica
There is growing concern about the environmental impacts and increasing difficulty to dispose preservative treated wood products at the end of their service life. In the next decades, in Portugal, a significant increase is expected in the amounts of treated wood that annually needs to be properly disposed. The recycling of these wastes, containing chromium, copper and arsenic (in the case of CCA-treated wood), should only be made after its remediation, so planning and optimisation of the remediation units locations is of major importance. The objective of this study is the development of a location model to optimise the location of remediation plants for the treatment of CCA-treated wood waste for further recycling, minimizing costs and respecting environmental criteria. The location model was implemented with geographic information using Geographic Information Systems (ArcGIS 8.2 © ESRI). All the uses of treated wood products were considered, using soil occupation data and the results of a questionnaire sent to wood preservation industries. Two different clustering methods (Self-Organizing Maps and K-means) were tested in different conditions to solve the multisource Weber problem using SOMToolbox for MATLAB. The solutions obtained with our data and with both clustering methods make sense and could be used to decide on the location of these plants. SOM has provided more robust and reproducible results than k-means, with the disadvantage of longer computing times. The main advantage of k-means, compared to SOM, is the reduced computing time allied to the fact that it allows us to obtain the best solutions in the majority of the cases, in spite of bigger variances and more geographical dispersion.

Preserved, treated wood is commonly found in solid waste. Among the different types of preserved wood, chromated copper arsenate (CCA) treated wood recently has received much attention due to the scale of usage and its significant role in soil and water contamination. As the ash of CCA treated wood is hazardous, it cannot be burned, and the best available disposal method is thus landfilling. Leaching of the metals from disposed preserved wood in landfills pollutes the soil, water and the environment. The existing literature on leaching of CCA treated wood is reviewed, and several factors affecting leaching of the metals from wood, including pH of the leachant, temperature, the duration of leaching, the type of leachant are discussed. These factors affect each of the metals including chromium, copper and arsenic, differently. Definition and comparison of the effect of these mentioned factors on each preservative metal several experiments were performed. In all experiments ground wood (remaining at the top of sieve No. 10) was soaked in leachant (ratio 1:10). The leachants were nitric acid, sulfuric acid and acetic acid (0.1N), having pH values of 3, 4 and 5. They were left in an incubator for 5,10 and 15 days. The temperature of the incubator was set to 15C̕ for 15 days and then the experiment was repeated for temperatures 25C̕ and 35C̕. On the other hand to investigate the biodegradability of the leached wood, unleached wood and some of the leached wood samples were chosen. The necessary nutrients for growth of fungi and soil were added and the amount of generated CO 2 was measured through the experiment. The results of the experiments showed that sulfuric acid (pH3) is the most effective leachant. Most of the leaching happens in the first 5 days and temperature increases the amount of leached metals. The leached CCA wood is still resistant to biodegradation.

碩士
國立屏東科技大學
木材科學與設計系所
99
Chromated copper arsenate (CCA) is a common wood preservative. However, Taiwan has banned the use of the product for some constructions on April 1, 2007 because it is a human carcinogen and possibly poses a potential risk to groundwater. As a result, CCA-treated wood as a solid waste will be concerned with its treatment and disposal in the current and future. In the present study, the experimental CCA-treated wood materials were tested using the toxicity characteristic leaching procedure (TCLP) and isothermal shaking water bath test leaching procedure to identify chromium concentrations by colorimetric and inductively coupled plasma-mass spectrometry (ICP-MS) methods. It was found that all of leached chromium concentrations were below the official standard designated by the Environmental Protection Administration. Furthermore, the results of the leaching experiments showed that the pH of the leachants, and density and particle size of CCA-treated woods have significant effects on the leaching process, higher leached metal concentrations in light and small size woods and low pH environment. Based on the experimental results, it was suggested that the CCA-treated woods should be separated from woody waste. The segregated CCA-treated woods were further treated using extraction to reduce their toxic metal hazards prior to the recycling or the reuse as energy sources.

Foram imersos em zonas costeiras (Sagres: Portugal; Portsmouth: U.K.) painéis de madeira tratada com crómio-cobre-arsénio (CCA) e de madeira controlo. Efectuaram-se colheitas de organismos (Mytílus spp.) aderidos aos paineis, após 12 e 18 meses de imersão, para análise de metais (Cr e Cu) na parte edivel. Compararam-se as concentrações de metais nos mexilhões, entre os diferentes locais e alturas de amostragem. Foi determinado o efeito da carga de CCA nas concentrações de metais. Foram imersos em água-do-mar pequenos blocos de madeira tratada com CCA e de madeira controlo, sob condições laboratoriais. Monitorizaram-se as concentrações de metais (Cr e Cu) nas soluções de água-domar. Deterrninou-se a taxa de libertação de metais e a sua relação com o tempo de imersão e com a carga de CCA. Estudou-se a sobrevivência de Artemia salina exposta às soluções de água-do-mar. Os resultados demostraram que os níveis de crómio nos organismos de Portsmouth eram mais baixos do que nos de Sagres. Não se verificou uma relação signjficativa entre carga de CCA e os niveis de crómio. Os níveis de cobre nos organismos de Sagres (12 meses) eram significativamente mais elevados do que nas restantes amostras; estes organismos também apresentavam um aumento das concentrações de cobre com o aumento da carga de CCA; esta relação não foi encontrada nas restantes amostras. Não foi libertado crómio, ou foi-o em pequenas quantidades, dos blocos de madeira. Por outro lado, foram libertadas quantidades significativas de cobre dos blocos tratados. A taxa de libertação foi semelhante entre as diferentes cargas de CCA estudadas e diminuiu com o tempo de acordo com a relação: |1gCu/cmz/h = a t`b (a e b são constantes e b>0). Não ocorreram efeitos letais em A. salina resultantes da exposição às soluções de água-do-mar. Os resultados observados foram discutidos em função de alguns factores biológicos e fisico-químicos.
Panels of chromated-copper-arsenate (CCA)-treated wood and control wood were immersed in coastal areas (Sagres: Portugal; Portsmouth: U.K.). Fouling organisms (Myfilus spp.) were collected after 12 and 18 months of wood immersion for metal (Cr and Cu) analysis in the soft tissues. Heavy metal levels in the mussels were compared between the different places and time of sampling. The effect of CCA loadings on metal concentrations was detennined. Small wood blocks of CCA-treated wood and control wood were immersed in sea-water, in laboratory conditions. Metal (Cr and Cu) concentrations in leachate solutions were monitorized. Metal release rate was determined and its relationship with leaching time and with CCA loading was investigated. Artemia salina survival exposed to leachate solutions was assessed. Chromium levels in the organisms from Portsmouth Were lower than in the ones from Sagres. There was not a significant relationship between CCA loading and chromium levels. Copper levels in the organisms from Sagres (12 months) were significantly higher than in the remaining samples; these organisms also presented higher copper concentrations with higher CCA loading; this relationship was absent in the remaining samples. Little or no chromium was released from the small blocks, while significant amounts of copper were released from the treated blocks. The release rate was similar between the different CCA loadings studied and decreased with time according to the relationship: |IgCu/cmg/h = a t"' (a and b are constants and b>0). There Were not lethal effects on A. salina from the exposure to leachate solutions. The observed results were discussed in relation to some biological and physicochemical factors.

Treated timber is a widely used construction material, as it is resistant to insect and fungal attack. The most commonly used timber treatment solution worldwide is copper chromium arsenate (CCA) pressure treated wood (APVMA 2005a). Environmental and health issues have been raised over CCA wood, with major particular concern raised on the possibilities of arsenic in the wood potentially leaching out. The Australian Pesticides and Veterinary Medicines Authority (APVMA) have limited its usage to minimise human contact with CCA structures (APVMA 2005a). In South Australia, CCA applications increased dramatically with the expansion of the winery industry where CCA treated timber posts were widely used for vineyard trellises. Due to the mechanical method by which most grapes are harvested, roughly 2% of all posts are broken and require disposal annually (SAEPA 2008). The Environmental Protection Agency of South Australia (EPASA) have placed restrictions on CCA disposal from vineyards (SAEPA 2004) and waste CCA stock is either stockpiled or sent to specially lined landfills incurring an estimated cost penalty of over $AU 200 per tonne¹ . Clearly, improved CCA treatment technologies must be developed to reduce (or eliminate) the cost of CCA disposal and to the footprint of land filled waste. CCA timber disposal techniques currently being researched are focussed primarily on thermal and biological routes. Thermal techniques are problematic due to volatilization of the arsenic in the product, whilst biological removal techniques are very slow. Chemical remediation is an alternative and attractive disposal technique of interest using various acids to extract copper, chromium and arsenic. Nitric acid has been shown to be particularly effective (Honda, Kanjo et al. 1991), although research has been limited. Nitric acid is also used in one method of paper pulp production, and as such, there is the potential for a combined CCA extraction and paper pulp process. This has the attraction of turning a waste in a value added product. The kinetics of copper, chromium and arsenic dissolution in nitric acid has been examined in this thesis. A key finding of the work identifies the size of CCA wood particles as the dominant factor affecting the extraction rate, whilst temperature and acid concentration only provide a minor effect. The extraction rate for all elements from CCA wood using nitric acid generally follow 2nd order kinetics. Concurrently, a study examining wood chips of various ages taken from vineyards was performed using chip sizes typical required for paper production. It was found that despite significant variations in the concentration profile of CCA in posts, a general model based on the fraction of each element could be created for posts of all ages. Over an 8 hour period, 65-80% of chromium, 50-70% of copper and 75-90% of arsenic was extracted from all posts. Given the excellent extraction observed under relatively simple nitric acid extraction, further studies on the applicability of nitric pulping for CCA remediation are recommended. Minimizing chip size subject to fibre size constraints in paper production is key to improved removal and additional means for enhancing chip surface area are identified. Other stages present in paper pulping process may solublize additional CCA and these warrant further investigation. A basic economic estimation was undertaken, where it was found that creating paper pulp from CCA wood could be economically feasible, but will require further research to determine the expected costs and revenues involved. The nature of the CCA wood waste was investigated. The expectation was that CCA posts would contain relatively consistent concentration profiles for copper, chromium and arsenic. However, it was observed that the concentrations were quite varied. Further, several posts produced during the wine boom in South Australia were very poorly treated with very poor penetration of the preservatives into the posts. This could result in a reduced lifetime for the posts, and potentially higher arsenic leaching than expected. It is also recommended that the frequency of these poorly treated posts be determined, as three of the six posts examined from this period were potentially poorly treated, implying it may be significant and unexpected problem. In addition, a study should be initiated to determine if these poorly treated posts are leaching higher levels of arsenic, by both a study of the surrounding soil and a simulated rainfall leaching experiment. Based on the concern that more arsenic leached from pieces of CCA post left in deionised water than expected, an experiment on posts of various ages revealed that over a 100 day period, 1.5-3g of elemental arsenic could leach from a submerged CCA treated post. There is a serious concern that with CCA posts being landfilled, they will be exposed to water contact over the wet months, resulting in high arsenic leaching. It is theorised that this high arsenic leaching is due to insufficient chromium in the CCA solution. Previous studies have recommended higher chromium to arsenic ratios than are currently employed in Australia. Further studies on the extent to which this leaching can occur in landfill are recommended. ¹ Personal communication with John Blumson, Zero Waste South Australia, 22/7/08.
Thesis (Ph.D.) -- University of Adelaide, School of Chemical Engineering, 2011

碩士
國立臺灣大學
森林環境暨資源學研究所
99
Chromated copper arsenate (CCA) is the most widely used wood preservative. It is formulated with copper, chromium, and arsenic oxides. Better disposal methods of CCA treated wood waste would be needed to alleviate secondary pollution induced by waste land-filling or incineration. There are many methods to remediate CCA treated wood waste. Aqueous extraction is the most one. In this study, the materials are southern pine (Pinus taeda) that is pressure-treated with CCA type C preservative (hexavalent chromium as CrO3, 47.5%; copper as CuO, 18.5%; arsenic as As2O5, 34.0%). Chelating agents are biodegradable chelating agents: ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA) and [S, S]-Ethylenediaminedisuccinic acid (EDDS). This study investigates impact of various parameters including pH, chelating concentration, temperature, and chelating duration on chromium, copper, and arsenic extraction efficiencies. Results indicates that lower pH (pH 2.0-4.0) are more effective than higher pH (pH>6) for extraction of chromium, copper, and arsenic. By changing solution concentration from 0.01 to 0.1M, the optimal extraction efficiencies for three metals were obtained at 0.1 M. Optimal extraction temperature for CCA metals was 75oC. The results of duration of extraction presented the chelating rates of metals. There is great extraction efficiencies of copper between 5 and 6 hours extraction. Under these best conditions, the highest percentage removals of chromium, copper and arsenic are 53%-66%, 84%-93%, 55%-62%, respectively. In the results of EDDS-CCA stoichiometric ratios, EDDS concentrations above unit stoichiometric requirement are required to remove CCA metals at optimal. And the extraction efficiencies are illustrated when solution to wood ratio is 10. The results of sequential extractions demonstrated that chromium was mainly existed in the organic and residual fractions (85.6%); copper is mainly existed in exchangeable and residual fractions (49%); arsenic is mainly existed in organic and residual fractions (80.2%). This study indicates the extraction efficiencies for chromium, copper, and arsenic by EDTA, EDDS and NTA are satisfactory. Besides, EDDS and NTA are more biodegradable, and more effect in CCA treated wood remediation. In the near future, EDDS and NTA could be applied broadly to remove heavy metals from wastes.

Preserved wood is commonly found in solid waste. Among the different types of preserved wood, CCA wood has received much attention due to the scale of usage and its significant role in soil and water contamination after disposal. As the ash of CCA wood is hazardous, it cannot be burned, and the best available disposal method is thus landfilling. Leaching of the metals from disposed CCA wood in landfills pollutes the environment. To reduce the contamination of CCA, treatment before landfilling is required. Nowadays, ethanol is seen as a promising source of energy. Lignocellulosic materials such as wood are resources for ethanol production. This research focuses on the possibility of producing ethanol from CCA wood. It suggests that production of ethanol will not only be a solution to the disposal but will also generate a clean fuel. The results showed the existence of copper, chromium and arsenic did not have a negative effect on the fermentation, and producing ethanol from CCA wood is feasible. The copper removed by sulfuric acid completely precipitated during the hydrolysis and iv neutralization. In addition about 50% of the chromium (VI) and also 60% of the arsenic (V) were removed from the leachate by yeast during fermentation. TCLP tests of the hydrolyzed wood leached less than 4 ppm of arsenic while minimal amounts of chromium and copper remained in the hydrolyzed wood which makes landfilling of hydrolyzed wood acceptable. Baker's yeast behaves selectively by uptaking arsenic (V) and chromium (VI) but not arsenic (III) and chromium (III). There is competition between copper and chromium sorption by yeast. The kinetic model for removal of copper and chromium is a zero order model while the appropriate model for uptaking arsenic by yeast is a first order model. The kinetic models confirm that there are different mechanisms of uptaking metals by yeast, a diffusion mechanism for removal arsenic and a surface adsorption mechanism for copper and chromium. As an overall conclusion of this study, using discarded CCA wood as the feed for ethanol production is a sustainable method for disposal of CCA treated wood.

碩士
長榮大學
職業安全與衛生研究所
95
Abstract The object of this study was aimed to determine the relationship between urinary chromium/arsenic and exposure levels of workers in CCA wood preservation plants in Taiwan. The monitoring of chromium and arsenic levels in urine and skin was performed on three wood preservation plants. The personal exposure data, customs, working time and frequency were collected with questionnaire. The samples from the workers were analyzed with atomic absorption spectrometry with graphite furnace (Varian, 220FS) and UV-Vis spectrophotometer (Varian Cary 50). The mean concentrations of hexavalent chromium and arsenic in the personal air samples were 0.12 ± 0.05 µg/m3 and 2.41 ± 1.35 µg/m3, all of them were below the PELs(As：0.01 mg/m3,Cr+6：0.1 mg/m3).The concentrations of chromium and arsenic in skin samples were 0.837 ± 0.398 mg and 2.621 ± 1.292 mg. The high concentration of asenic, chromium was distributed on the skin of hand and foot. The increased concentration during shift of chromium in urine was close to 10μg/L, the biological exposure index of chromium set by ACGIH. The concentration of chromium in urine samples collected at the end of workweek was in urine was close to 25μg/L the biological exposure index of chromium set by ACGIH. Urinary chromium concentrations were significantly associated with dermal exposure values. The increased concentrations during shift of arsenic and chromium in urine and skin samples were above over the suggested value set by ACGIH, it needs to continue following the trail of further. Base on the significant association between urinary chromium concentrations and dermal exposure index, we concluded the dermal exposure could be the major exposure route for body burden of chromium. The high concentration of asenic, chromium was distributed in skin of hand and foot; therefore, wearing impermeable gloves during working might reduce dermal exposure.

Savanna woodlands are vitally important in providing ecological services (e.g. erosion protection, micro-climate) and economic services (e.g. timber, food, fodder non-wood products, and wild-life habitats) that sustain local livelihoods and national economies. Increasing demands and the need for sustainable savanna woodland resource management requires that the ecological, economic, social and cultural values of these resources be explored and brought to the attention of decision makers and the general public. The identification and better understanding of the structure and dynamics of woodland community types, patterns of species distribution and quantitative properties of their diversity is important to the conservation and sustainable management of these woodlands. This study seeks to contribute to a better understanding of Nakasongola woodland community types, species diversity patterns and environment correlates, natural regeneration processes (i.e. sprouting and seedling establishment) and identifying livelihood strategies adopted by households, woody species utilised, and the contribution of charcoal production to household livelihoods. Data on vegetation and environmental variables were collected using 75 rectangular 20 x 50 m (0.1 ha) plots. Data on land use and land cover changes, and relevant associated socio-economic parameters were collected through the analysis of multi-temporal satellite imagery and field observations, as well as interviews of local households and key informants. The basic major livelihood activities for the rural households in this savanna dryland are charcoal production, subsistence crop cultivation and livestock grazing. However, it, sometimes, includes various combinations of activities, i.e. charcoal production and subsistence crop cultivation for both food and cash, and livestock keeping for income generation through selling the livestock products such as milk and, sometimes, the whole animal. At least 24 woody species, including fruit trees (Mangifera indica and Artocarpus heterophyllus), are frequently harvested, including 16 species that are considered the most utilized for charcoal production. Charcoal production, being the major source of income to the rural households, contributes on average US$ 259 ± 46 (S.E.) per household annually. There were significant differences in charcoal production (Kruskal-Wallis; H = 31.42, p < 0.0001), producer sale prices per bag of charcoal (H = 35.62, p < 0.0001), and annual incomes from charcoal production (H = 32.44, p < 0.0001) per households across the 8 sub-counties. Most of the youth (≤ 20 years old) derive their livelihoods from charcoal production, a small amount of trade, offering labour services, livestock keeping, fishing, bee keeping and earth brick making. Charcoal production, livestock keeping and hunting are carried out particularly by men, whereas, crop cultivation, and collection of fire wood, medicinal plants and fruits are carried out, mainly, by women. However, men are also engaged in cultivation only during the rainy seasons. There have been significant land cover changes in the area during the period 1984 to 2001, resulting in a 64% decrease in dense woodland cover, and an 80% increase in areas under cultivation/settlements. These changes are attributed to significant spatial expansion in agriculture increased commercialisation of charcoal production, grazing and human population growth. A total of 44,195 (5,893 plants/ha) woody plants representing 99 species in 67 genera and 31 families were recorded. The most species rich families were Mimosaceae (13), Rubiaceae (9), Moraceae (7), Euphorbiaceae (7), Anacardiaceae (6), Combretaceae (5) and Verbenaceae (5). Density of woody species differed significantly (F2, 72 = 6.3, P < 0.003) among land uses, being higher under charcoal production (7,131 ± 755 plants/ha) and cultivation (6,612 ± 665) areas and significantly lower under grazing lands (4,152 ± 525). Community species composition differed significantly (Global RANOSIM = 0.14, p = 0.001) among land use types. All measures of beta-diversity (spatial “turnover” in species composition) showed consistently higher beta-diversity in the grazing land use (βW = 3.1; βT = 3.1), followed by cultivation (βW = 2.8; βT = 3.0) and charcoal production (βW = 2.7; βT = 2.8), suggesting a more heterogeneous spatial distribution of species in the grazing lands. This suggests that variations in the composition and diversity of woody species are to a great extent influenced by land use type and anthropogenic disturbances in this region. Basal area of woody species differed significantly (F2, 72 = 12.0, P < 0.0001) among land uses, being highest under cultivation and charcoal production and significantly lower under grazing. Woody plant density differed (F2,72 = 6.3, P = 0.003) across landuses, being highest under charcoal production and cultivation and significantly lower under grazing. The species that contributed most to both basal area and density across all the land uses were Combretum collinum and Combretum molle. However, different species contributed the next most i.e. Piliostigma thonningii for grazing; Albizia zygia and Harrisonia abyssinica for cultivation and Vepris nobilis for charcoal production areas. For both basal area and abundance of all woody species, the total variance in species-environmental factor relations (for the combined first four canonical axes) was higher than 50%, suggesting a relatively strong influence of the measured environment variables on species composition and distributions. The CCA points to a significant influence of soil Ca2+ and Mg2+ in association with grazing on gradients in the composition and structure of woody species in the savanna woodland of Nakasongola. Resprouting was generally common among the woody species. A total of 2,595 stumps, representing 74 species in 31 families were recorded from all plots. Of these, 98.3% resprouted and were identified to species level. Density of both stumps and total resprout differed significantly (p < 0.05) among the land uses, being higher in charcoal production areas than in grazing and cultivation land uses. For the overall pooled data, resprouts per stump differed significantly among land uses (F2, 456 = 7.75, p = 0.0005), being highest in charcoal production (mean ± S.E.; 14 ± 1) and cultivation (13 ± 1) land uses and lowest under grazing areas (10 ± 1). Generally, the mean number of resprouts per stump increased with increasing stump basal diameter (BD), being highest for BD size class > 41 cm. In relation to stump height, the highest mean resprouts/stump was found on stumps with heights ranging from 0.31- 0.40 m. Based on pooled species data, regression analyses showed weakly significant negative relationships between BD of leading resprouts and number of resprouts/stump (r2 = 0.123, p < 0.0001) and between height of leading resprouts and number of resprouts/stump (r2 = 0.068, p < 0.0001). Density of seedlings of woody species differed significantly among land use types (ANOVA; F2, 72 =5.9, p = 0.004), being highest for cultivation (3,162 ± 440 individuals ha-1), followed by charcoal production (2,416 ± 295 ha-1) and lowest for grazing (1,629 ± 205 ha-1). Composition of seedlings differed significantly among land use types (Global RANOSIM = 0.119, p = 0.001). The distributions and densities of some seedlings were explained by gradients in environmental variables, with edaphic factors (i.e. Ca2+, Mg2+, K+ and organic matter) and charcoal production being the most important. The first two axes of the Canonical Correspondence Analysis (CCA) explained 41.9% of the variance in species – environmental relations and were a reflection of edaphic and charcoal production land use gradients. All of the 16 highly utilized species were well represented in both the juvenile and adult classes, with gradually declining number of individuals with increasing stem size-class. This indicates that most of these species have high regeneration potential. Juvenile:adult tree ratios >1 and negative DSCD slopes indicate good recruitment and probably successful regeneration for these species. The study revealed land cover changes mainly in the dense and medium dense woodlands, reflected by the increase in open woodland, grasslands and cultivation/settlements. These trends threaten the livelihoods of local communities who are entirely dependent on these natural resources. Sustainable management will require the establishment of suitable integrated community-based institutions and management practices, with support from all key stakeholders (i.e. National Forest Authority (NFA)) and local communities. Maintenance of savanna woodland resources and other ecosystem services essential for human well-being will require an effective legal framework to prevent over-exploitation and give incentives for the protection of the fragile savanna woodland vegetation. An appropriate savanna woodland management policy will be required to guide changes in land use that accommodate the requirements of land users, aided by targeted conservation efforts to all woody plants and particularly for the highly utilized species for charcoal production as well as the multipurpose species. In addition, there is urgent need to build local capacity for improved harvesting and utilization of these tree species. This can be achieved through equipping local users with up to date information as well as observing the existing skills.