A contaminação do solo é uma das fontes pela qual os contaminantes são escoados para os ecossistemas aquáticos, afetando a qualidade dos sedimentos. Neste compartimento alguns compostos são capazes de bioacumular e interferir nos fluxos de energia e de nutrientes da cadeia biológica, gerando efeitos agudos, crônicos e genotóxicos para as comunidades que vivem ou entram em contato com este local. A região de estudo está localizada em área às margens do rio Taquari, no município de Triunfo, RS, próxima a um sítio com solo contaminado por preservantes de madeira, com passivo ambiental identificado (creosoto, pentaclorofenol e a hidrossal CCA). Esta área foi submetida à primeira fase do processo de intervenção para retirada das principais fontes ativas. Em estudos anteriores foi definido o provável escoamento de contaminantes para o rio a partir do solo contaminado. Para avaliar a qualidade dos sedimentos, nas diferentes fases de intervenção da área, foi utilizado o ensaio Salmonella/microssoma, para avaliar mutagênese, além da dosagem de HPAs nos extratos orgânicos de sedimentos. Foram testados quatro áreas de coleta, identificadas pela distância em Km a partir da foz, abrangendo local a montante do sítio, Ta032, em frente, Ta010, e a jusante, Ta006 e Ta004. As coletas foram nas fases, antes (inverno e verão), durante (verão) e após (verão) o processo de intervenção. A mutagênese foi avaliada através de linhagens que medem erro no quadro de leitura (TA98 e Ta97a) e substituição de pares de bases (TA100), na presença e ausência de S9mix (±S9) em extratos de compostos moderadamente polares de sedimento. Os resultados indicaram presença de pró-mutágenos em todas as amostragens na área Ta010, sendo mais elevada na anterior à intervenção (verão) para TA100+S9 (1672 rev/g) decrescendo durante e após este processo. Foram também observados valores constantes de HPAs totais e presença das espécies com potencial cancerígeno nos diferentes períodos avaliados. O local Ta006, após a intervenção, foi o que mostrou mutagênese mais alta (764 rev/g), sendo que as espécies consideradas cancerígenas foram detectadas em maiores concentrações, em especial o benzo(b+k) fluoranteno, que também esteve elevado, neste período, em Ta004. Presença de mutagênese e HPAs em arroio interno ao sítio, a montante de Ta010, marcaram uma das rotas de dispersão dos contaminantes. A presença de contaminação em frente ao sítio, após a intervenção, pode estar relacionada com a técnica escolhida para retirada das fontes ativas, contribuindo na presença de contaminantes a jusante deste rio, Ta006 e Ta004. / Soil contamination is one fo the sources of contaminant runoff into acquatic system, affecting sediment quality. In this compartment some compounds can bioaccumulate and interfere in the energy and nutrient flux of the biological chain with acute, chronic and genotoxic effects on the communities who live there or have contact with this place. The region studied is located on the area on the banks of Taquari river, in the municipality of Triunfo, RS, close to a site with soil contaminated by wood preservatives and identified environmental liabilities (creosote, pentachlorophenol and hydrosalt CCA). This area was submitted to the first stage of the intervention process to remove the main active sources. Previous studies defined the probable runoff of contaminants into river from contaminated soil. In order to evaluate the sediment quality in the different phases of intervention in the area, the Salmonella/microsome assay was used to evaluate mutagenesis, besides the dosage of PAHs in the sediment organic extracts. Four collection areas were tested, identified by the distance in km from the mouth, covering a location upstream from the site, Ta032, in front, Ta010, and downstream, Ta006 and 004. The collections were performed in the phases, before (winter and summer), during (summer) and after (summer) the intervention process. Mutagenesis was evaluated using frameshift (TA98 and Ta97a) and base pair substitution (TA100) strains in the presence and absence of S9mix (±S9), in extracts of moderately polar sediment compounds. The results indicate the presence of promutagens in all samplings in the Ta010 area, and it is higher before the intervention (summer) for TA100+S9 (1672 rev/g) decreasing during and after this process. Constant values of total PAHs and presence of species with a carcinogenic potential were also observed in the different periods evaluated. Site Ta006, after intervention, showed the highest mutagenesis (764 rev/g), and the species considered carcinogenic were detected at higher concentrations, especially benzo(b+k) fluoranthene, which was also high during this period at Ta004. The presence of mutagenesis and PAHs in a stream inside the site, upstream from Ta010 marks one of the contaminant dispersion routes. The presence of contamination in front of the site after intervention may be related to the technique chosen to remove the active sources, contributing to the presence of contaminants downstream of this river, Ta006 and Ta004.

A contaminação do solo é uma das fontes pela qual os contaminantes são escoados para os ecossistemas aquáticos, afetando a qualidade dos sedimentos. Neste compartimento alguns compostos são capazes de bioacumular e interferir nos fluxos de energia e de nutrientes da cadeia biológica, gerando efeitos agudos, crônicos e genotóxicos para as comunidades que vivem ou entram em contato com este local. A região de estudo está localizada em área às margens do rio Taquari, no município de Triunfo, RS, próxima a um sítio com solo contaminado por preservantes de madeira, com passivo ambiental identificado (creosoto, pentaclorofenol e a hidrossal CCA). Esta área foi submetida à primeira fase do processo de intervenção para retirada das principais fontes ativas. Em estudos anteriores foi definido o provável escoamento de contaminantes para o rio a partir do solo contaminado. Para avaliar a qualidade dos sedimentos, nas diferentes fases de intervenção da área, foi utilizado o ensaio Salmonella/microssoma, para avaliar mutagênese, além da dosagem de HPAs nos extratos orgânicos de sedimentos. Foram testados quatro áreas de coleta, identificadas pela distância em Km a partir da foz, abrangendo local a montante do sítio, Ta032, em frente, Ta010, e a jusante, Ta006 e Ta004. As coletas foram nas fases, antes (inverno e verão), durante (verão) e após (verão) o processo de intervenção. A mutagênese foi avaliada através de linhagens que medem erro no quadro de leitura (TA98 e Ta97a) e substituição de pares de bases (TA100), na presença e ausência de S9mix (±S9) em extratos de compostos moderadamente polares de sedimento. Os resultados indicaram presença de pró-mutágenos em todas as amostragens na área Ta010, sendo mais elevada na anterior à intervenção (verão) para TA100+S9 (1672 rev/g) decrescendo durante e após este processo. Foram também observados valores constantes de HPAs totais e presença das espécies com potencial cancerígeno nos diferentes períodos avaliados. O local Ta006, após a intervenção, foi o que mostrou mutagênese mais alta (764 rev/g), sendo que as espécies consideradas cancerígenas foram detectadas em maiores concentrações, em especial o benzo(b+k) fluoranteno, que também esteve elevado, neste período, em Ta004. Presença de mutagênese e HPAs em arroio interno ao sítio, a montante de Ta010, marcaram uma das rotas de dispersão dos contaminantes. A presença de contaminação em frente ao sítio, após a intervenção, pode estar relacionada com a técnica escolhida para retirada das fontes ativas, contribuindo na presença de contaminantes a jusante deste rio, Ta006 e Ta004. / Soil contamination is one fo the sources of contaminant runoff into acquatic system, affecting sediment quality. In this compartment some compounds can bioaccumulate and interfere in the energy and nutrient flux of the biological chain with acute, chronic and genotoxic effects on the communities who live there or have contact with this place. The region studied is located on the area on the banks of Taquari river, in the municipality of Triunfo, RS, close to a site with soil contaminated by wood preservatives and identified environmental liabilities (creosote, pentachlorophenol and hydrosalt CCA). This area was submitted to the first stage of the intervention process to remove the main active sources. Previous studies defined the probable runoff of contaminants into river from contaminated soil. In order to evaluate the sediment quality in the different phases of intervention in the area, the Salmonella/microsome assay was used to evaluate mutagenesis, besides the dosage of PAHs in the sediment organic extracts. Four collection areas were tested, identified by the distance in km from the mouth, covering a location upstream from the site, Ta032, in front, Ta010, and downstream, Ta006 and 004. The collections were performed in the phases, before (winter and summer), during (summer) and after (summer) the intervention process. Mutagenesis was evaluated using frameshift (TA98 and Ta97a) and base pair substitution (TA100) strains in the presence and absence of S9mix (±S9), in extracts of moderately polar sediment compounds. The results indicate the presence of promutagens in all samplings in the Ta010 area, and it is higher before the intervention (summer) for TA100+S9 (1672 rev/g) decreasing during and after this process. Constant values of total PAHs and presence of species with a carcinogenic potential were also observed in the different periods evaluated. Site Ta006, after intervention, showed the highest mutagenesis (764 rev/g), and the species considered carcinogenic were detected at higher concentrations, especially benzo(b+k) fluoranthene, which was also high during this period at Ta004. The presence of mutagenesis and PAHs in a stream inside the site, upstream from Ta010 marks one of the contaminant dispersion routes. The presence of contamination in front of the site after intervention may be related to the technique chosen to remove the active sources, contributing to the presence of contaminants downstream of this river, Ta006 and Ta004.

The feasibility of using modified nano-chitosan particles as an environmentally friendly wood preservative agent was investigated in this research. Chitosan nano-particles were prepared from commercially available low molecular weight (LMW) chitosan and its derivative, trimethyl chitosan (TMC). The specific amount of sodium nitrite added to LMW chitosan through depolymerization process indicated the desired chitosan oligomers. Thin layer chromatography (TLC) was done to confirm the formation of chitosan oligomers with degree of polymerization four. Preparation of TMC was done through a quaternization process and Fourier-transform infrared spectroscopy (FTIR) graphs proved the formation of TMC. Sodium tri-poly phosphate (TPP) as a commercial fire retardant was added to these nanoparticles (chitosan oligomers and TMC) to form nanochitosan-TPP particles based on the ionic gelation method. The viscosity of chitosan nanoparticles which were made by chitosan oligomers and TMC were measured by rheometer. The results showed very low viscosity in comparison to LMW chitosan. The final concentration of chitosan oligomers, TMC and TPP in the nano-chitosan-TPP solution to treat wood were 12, 12 and 4.8% respectively. Then, these particles were used to treat southern yellow pine wood through vacuum impregnation process. Mass and volume of samples increased after treatment which means the nano-chitosan-TPP particles penetrated into cell walls. To study the leaching of treated samples, they were soaked to water according to the E11 standard test (AWPA, 2016) and to investigate the fungi resistance of treated samples, they were exposed to brown rot fungus (Gloeophyllum trabeum) and white rot fungus (Trametes versicolor) according to the E10 standard test (AWPA, 2016). Mass loss of the samples was compared to untreated wood controls. The results of leaching and fungi indicated that non quaternized nanochitosan-TPP particles were more effective than quaternized nanochitosan-TPP particles. Measuring the fire resistance and water vapor sorption isotherm of treated samples revealed that there were not any differences among treated and control samples.

This research focuses on the evaluation of many aspects of the American Wood Protection Association (AWPA) Standard E1-97, “Standard Method for Laboratory Evaluation to Determine Resistance to Subterranean Termites.” This standard is used extensively for testing the efficacy of new products and preservative systems against subterranean termite species. Research was done to determine what changes, if any, are needed for testing against subterranean termite species such as Coptotermes formosanus (Shiraki) and species of native termite genus Reticulitermes (Holmgren), primarily R. flavipes (Kollar). Variables from the current standard were tested to determine effects of parameters such as moisture of sand substrate; size, type, and location of test material within a test bottle; and termite number and ratios of workers to soldiers per test bottle. Research also improved comprehension of termite biology in a laboratory setting, enabling researchers to develop new and safer control methods.

A study was undertaken during June through September, 1981, in which the periphyton from ten locations in Culpeper, Virginia, were analyzed for arsenic, chromium, and copper, both upstream and downstream from the source of contamination. The periphyton primary productivity, chlorophyll-a content, and autotrophic index were also determined. Water samples were analyzed for the three metals; arsenic, chromium, and copper. The highest mean periphyton arsenic and chromium concentration occurred at the station 1.2 miles below the site of contamination. The copper concentration in the periphyton was highest 2.7 miles below the area of contamination. All three periphyton metal concentrations were dependent upon the location of the sampling site, but only the periphyton copper content was dependent upon the date of sampling. All three periphyton metal concentrations below the spill site were higher than normal concentrations found in uncontaminated periphyton. Periphyton primary productivity was greatest at the station above the spill site and lowest at the site 1.2 miles below the site of contamination. A negative correlation was observed between the productivity and the periphyton chromium concentration. No other relationships were noted. The chlorophyll-a level in the periphyton was dependent only upon the date of sampling, not on the location of the sampling site. No relationships were observed between the chlorophyll-a levels and any of the three metals' concentrations in the periphyton. The autotrophic indices, the ratio of the organic matter to the periphyton chlorophyll-a concentration, were very high at all stations, indicating organically polluted water. Both the location and date of sampling significantly affected the autrophic index. / Master of Science

This study was designed to investigate potential environmental effects of stream contamination resulting from a spill by Culpeper Wood Preservers, Culpeper, Virginia. The objective was to determine the concentrations of arsenic, chromium, and copper in the sediments of streams affected by the spill and by runoff from a landfill site. The variations in metal concentrations were studied as functions of depth within the stream bed, as functions of distance from the source of contamination, and with passage of time. Sediments from several locations along the streams were extracted with Hcl and analyzed to determine metals concentrations. A microcosm experiment was conducted also to determine whether metals in the sediments would be released to the water under anaerobic conditions. Concentrations as high as 16 ppm for arsenic and 114 ppm for chromium were found in the sediment downstream of Culpeper Wood Preservers. Copper levels were not significantly higher than natural levels. Little difference was found between concentrations of shallow and deeper sediments. Downstream from the landfill site, metal concentrations were not significantly greater than natural concentrations for most sampling locations. In the microcosm experiments, chromium and copper were not released from the sediment. Arsenic concentrations in the water initially increased, then declined. The major conclusion of the study was that the metals appeared to be bound in the sediment and, except for potential releases of arsenic in anaerobic pools during low flow conditions, they should remain in the bound state. / M.S.

Studies were conducted on the penetration and permanence of 1.0% chlorpyrifos [0,0-diethyl 0-(3,5,6-trichloro-2-pyridyl) phosphorothioate], formulated as Dursban® TC (Dow Chemical Co.), in pine (Pinus spp.), spruce (Picea spp.), and fir (Abies spp.). Results indicated the highest degree of penetration in southern yellow pine. Surface roughness and orientation had an effect upon chemical penetration. Longevity studies ranging over time periods from three to 52 months revealed rapid loss of chlorpyrifos from the surface of the wood but relatively stable below-surface concentrations. Similar studies with 0.5% permethrin [(3-phenoxypheny]) methyl] (+) - cis, trans-3-(2,2-dichloroethenyl)-2,2dimethylcyclopropane-carboxylate] applied to the same wood types revealed comparable penetration differentials between types of wood. Formulation differences had little significant effect on penetration. One-year longevity studies revealed surface losses less drastic than those reported for chlorpyrifos, as well as superior below-surface stability. Studies employing volumes five, 10, and 25 times less than that required to achieve a runoff application revealed significantly lower chlorpyrifos penetration with reduced volume. Some reduced volumes resulted in below-surface concentrations of chlorpyrifos higher than the LC₉₀ value for Hylotrupes bajulus (Coleoptera: Cerambycidae). Toxicity testing with chlorpyrifos on first-instar larvae of H. bajulus, the old house borer, revealed contact LC₅₀ and LC₉₀ values of 14 ppm and 78 ppm, respectively. Similar tests with permethrin indicated LC₅₀ and LC₉₀ values of 2 ppm and 8 ppm. Tests with first-instar larvae on wood treated with 1.0% chlorpyrifos and 0.5% permethrin resulted in 100% mortality on wood aged for nine months in the case of chlorpyrifos, and six months in the case of permethrin. Tests utilizing H. bajulus eggs placed on treated wood revealed ovicidal properties of permethrin and lack of ovicidal effect with chlorpyrifos. Accelerated ageing studies employing an environmental chamber (40°C, 70% RH) at a 1:6 ratio of accelerated to natural weathering indicated no significant difference in surface or below-surface concentrations of permethrin in wood aged artificially for one month and in wood aged naturally for six months. Similar results were obtained with chlorpyrifos-treated wood artificially aged for 10 months and aged naturally for 4-1/3 years. Mathematical models were developed to predict surface and one millimeter concentrations of chlorpyrifos and permethrin after five and 10 years. / Ph. D.

Wood-based panel products (WBPs) are considered highly sustainable due to their carbon neutrality, low embodied energy, and ability to be produced from various low-grade wood species. However, WBPs exhibit limited resistance to biological degradation, which can deteriorate their mechanical performance and shorten their service life. Additionally, WBPs may not be fully compatible with traditional wood preservation chemicals. This dissertation demonstrated a facile method of synthesizing essential oil-based natural preservatives compatible with WBPs. Four essential oils (EOs), namely thymol (THY), trans-cinnamaldehyde (tCN), carvacrol (CRV), and eugenol (EUG), were complexed with beta-cyclodextrin (beta-CD) to form beta-CD-EOs inclusion complexes through a sonochemical process using a high-power ultrasonicator (750W). The sonochemical variables, such as a molar ratio between beta-CD and EO, ultrasonication power, and centrifugation speed and time, were optimized to improve the inclusion yield of EOs in the complex and facilitate the large-scale production of beta-CD-EOs. Attenuated Fourier transform infrared spectroscopy (AT-FTIR) and X-ray diffraction analysis confirmed the formation of inclusion complexes at the different production scales. The inclusion yield of EOs in the complexes was estimated by ultraviolet-visible spectrophotometry (UV-vis) as well as thermogravimetric analysis (TGA), which was capable of differentiating unreacted EOs and loosely encapsulated EO molecules from the estimation of the inclusion yield. Differential scanning calorimetry (DSC) revealed that beta-CD-tCN did not adversely affect the curing properties of polymeric methylene diisocyanate (pMDI) used as a glue for plywood. The influence of beta-CD-tCN addition on the bonding strength of the wood composite was assessed by a lap shear strength test using 3-ply SYP plywood, following ASTM D906-20. Statistical analysis using the Tukey test at p<=0.05 indicated no significant difference between the bonding strength of pMDI and beta-CD-tCN as an additive, indicating that beta-CD-tCN could be successfully implemented in the manufacturing process of wood composite products as natural preservatives.

Mechanisms of adsorption of alkaline copper quat (ACQ) components in wood were investigated with emphasis on: copper chemisorption, copper physisorption, and quat adsorption. Various factors were investigated that could affect the adsorption of individual ACQ components in red pine wood. Copper chemisorption in wood was affected by ligand types coordinating with Cu and the stability of the Cu-ligand complexes in solution. For Cu-monoethanolamine (Cu-Mea) system, the prevailing active solvent species at the solution pH, [Cu(Mea)2-H]+ complexes with wood acid sites and loses one Mea molecule through a ligand exchange reaction. The amount of adsorbed Cu was closely related to the cation exchange capacity of wood. An increase in Mea/Cu ratio increased the proportion of the uncharged Cu-Mea complex and resulted in decreased Cu chemisorption in wood. Copper precipitation is also an important Cu fixation mechanisms of Cu-amine treated wood. X-ray diffraction analysis revealed that in vitro precipitated Cu was a mixture of copper carbonates (azurite and malachite) and possibly Cu2O. Higher concentration Cu-amine solutions retarded the Cu precipitation to a lower pH because of higher free amine in the preservative-wood system. The changes in zeta potential of wood in relationship to the quaternary ammonium (alkyldimethylbenzylammonium chloride: ADBAC) adsorption isotherm showed two different adsorption mechanisms for quat in wood: ion exchange reaction at low concentration and additional aggregation form of adsorption by hydrophobic interaction at high concentration. Because of the aggregation effect, when wood was treated with ACQ, high amounts of ADBAC were concentrated near the surface creating a steep gradient with depth. This aggregated ADBAC was easily leached out while the ion exchanged ADBAC had high leaching resistance. Free Mea and Cu of ACQ components appeared to compete with ADBAC for the same bonding sites in wood.

Mechanisms of adsorption of alkaline copper quat (ACQ) components in wood were investigated with emphasis on: copper chemisorption, copper physisorption, and quat adsorption. Various factors were investigated that could affect the adsorption of individual ACQ components in red pine wood. Copper chemisorption in wood was affected by ligand types coordinating with Cu and the stability of the Cu-ligand complexes in solution. For Cu-monoethanolamine (Cu-Mea) system, the prevailing active solvent species at the solution pH, [Cu(Mea)2-H]+ complexes with wood acid sites and loses one Mea molecule through a ligand exchange reaction. The amount of adsorbed Cu was closely related to the cation exchange capacity of wood. An increase in Mea/Cu ratio increased the proportion of the uncharged Cu-Mea complex and resulted in decreased Cu chemisorption in wood. Copper precipitation is also an important Cu fixation mechanisms of Cu-amine treated wood. X-ray diffraction analysis revealed that in vitro precipitated Cu was a mixture of copper carbonates (azurite and malachite) and possibly Cu2O. Higher concentration Cu-amine solutions retarded the Cu precipitation to a lower pH because of higher free amine in the preservative-wood system. The changes in zeta potential of wood in relationship to the quaternary ammonium (alkyldimethylbenzylammonium chloride: ADBAC) adsorption isotherm showed two different adsorption mechanisms for quat in wood: ion exchange reaction at low concentration and additional aggregation form of adsorption by hydrophobic interaction at high concentration. Because of the aggregation effect, when wood was treated with ACQ, high amounts of ADBAC were concentrated near the surface creating a steep gradient with depth. This aggregated ADBAC was easily leached out while the ion exchanged ADBAC had high leaching resistance. Free Mea and Cu of ACQ components appeared to compete with ADBAC for the same bonding sites in wood.