<p dir="ltr">The frequency and intensity of wildfires occurring at the wildland-urban interface is increasing, and public drinking water systems operating in these communities are at risk. Widespread volatile organic compound (VOC) and semi-VOC (SVOC) contaminations have been detected in water distribution systems, often at concentrations above regulatory limits. Uncertainty about the source and fate of these contaminants has hindered recovery efforts. It is hypothesized that one source of the contaminants is the thermal degradation of plastic components within water distribution systems. Plastics are commonly used for water conveyance due to their low cost and ease of installation. However, plastics are vulnerable to thermal degradation, and have been shown to release VOC/SVOCs into the air when thermally degraded. Further, certain plastics such as polyethylene, are vulnerable to organic compound permeation, which could result in the contamination of otherwise undamaged components. This dissertation is comprised of four studies aimed at evaluating if plastic components within water distribution systems may be a source of contamination post-wildfire.</p><p dir="ltr">First, the aqueous leaching from commercial drinking water pipes was evaluated following thermal degradation in air. In this work, eleven plastic drinking water pipes were exposed to elevated temperatures (200°C to 400°C), and subsequently submerged in water or in <i>n</i>-hexane to observe the extent of VOC leaching. Results indicated that thermally damaged drinking water pipes can be sources of VOC leaching, with ten of the eleven materials leaching benzene, a carcinogen, into water. As exposure temperature increased, there was an increase in VOC leaching from the polyethylene plastics. Conversely, in the vinyl plastics the significant mass loss associated with high exposure temperature was inversely proportional to the amount of leaching that was observed.</p><p dir="ltr">The second study determined how the direct contact of water during plastic thermal degradation impacts the formation and aqueous leaching. Experiments were carried out using a continuously stirred tank reactor (CSTR) to expose plastics to a range of temperature (100°C to 300°C) in the presence of water. Five polyethylene materials were tested, including three cross-linked polyethylene (PEX) pipes, one high-density polyethylene pipe (HDPE), and one HDPE resin. Following degradation, clean water was pumped through the reactor to evaluate the efficacy of flushing to remove contaminants from thermally damaged plastics. Again, material type and exposure temperature impacted the leaching profile. Flushing removed contaminants from the thermally damaged plastics, however the removal rate varied based on chemical properties. Exhumed materials from wildfire impacted water systems were extracted in water to assess similarities and leached up to twelve different compounds, seven of which were also detected in laboratory experiments.</p><p dir="ltr">The third study investigated the impact of polyethylene formulation on aqueous leaching following thermal degradation to further understand the underlaying phenomenon causing the formation and leaching of contaminants. The impact of resin density, antioxidant type (Irganox 1010^® or Irgafos 168^®), antioxidant dose (0 to 10 wt. %), and impact of carbon black (0 or 2 wt. %) was investigated by compounding 12 different composites and thermally degrading them in the CSTR reactor described previously. Results found that all variables tested impacted the observed leaching. The addition of antioxidants decreased the observed leaching of polyethylene degradation products but increased the leaching of a variety of antioxidant degradation products. Carbon black was found to interact with the antioxidants during compounding, leading their consumption, and as a result decreased their effectiveness in protecting the polymer chain.</p><p dir="ltr">Lastly, the susceptibility of plastic water supply connectors such as ice-maker lines, faucet connectors, and washing machines hoses was assessed. The vulnerability of rigid plastic materials within water systems has been well studied, however, water supply connectors tend to be made of flexible plastics such as plasticized PVC and low-density polyethylene, and limited data exists on the susceptibility of these materials to contamination. In this study, seven connectors were exposed to hydrocarbon contaminated water, and subsequently decontaminated by water flushing. Following an initial 24 h contamination period, water samples were collected at three consecutive periods of 72 h. Results found that all materials sorbed more than 90% hydrocarbon contaminants. All materials released contaminants into the water during decontamination, at times above health-based limits. The majority of sorbed mass remained in the plastics at the end of the decontamination periods.</p>

High concentrations of heavy metals in the soils have potential long-term environmental and health concerns because of their persistence and accumulation tendency in the environment and along the food chain. This study was aimed at studying the feasibility of heavy metals removal from the soil using plants naturally growing in the surroundings of selected polluted sites in Tanzania and soil application of the sorbent materials zeolite and autoclaved aerated concrete (AAC). The results showed that Sporobolus sp. is a hyperaccumulator of Cu. Four other species, Launea cornuta (Oliv &amp; Hiern) O. Jeffrey, Tagetes minuta (L.), Sporobolus sp. and Blotiella glabra (Bory) Tryon showed high potential for phytoextraction of Cu. No hyperaccumulators of Pb and Zn were identified in the area, but Tephrosia candida and Tagetes minuta (L.) were identified as potential plants for phytoextraction of Pb, while Conyza bonariensis (L.) Cronquist, Launea cornuta (Oliv &amp; Hiern) O. Jeffrey, Tagetes minuta (L.), Blotiella glabra (Bory) Tryon, Pteridium aquilinum (L.) Kulm and Polygonum setogulum A. Rich were identified as potential plants for phytoextraction of Zn. The result from sorbent experiments showed that both materials had a potential for remediating metal polluted soils. The AAC had a higher removal capacity for both Zn and Pb than zeolite. The removal capacity of zeolite and AAC in a mixed metal experiment (Pb and Zn) showed a little difference in the sorption capacity of AAC and Zeolite for Pb and Zn respectively. Speciation of the metal in soil shows that the major part of the metal was associated with firmly attached component of the metal in the soil. Compared with the total metal concentration analysed, the available component accounted for 13-39% for Zn and 31-39% for Pb. It can be suggested to co-remediate polluted soils using reactive sorbent nodules and hyper-accumulating plant species. Identification of the best combinations and designs remains the subject of future research. / <p>QC 20121130</p>

No description available.

As lesões da periimplantite se não tratadas propriamente podem levar à reabsorção óssea e conseqüente perda do implante. Os implantes com superfície rugosa apresentam melhor resposta do tecido ósseo e melhor ancoragem, entretanto facilitam a formação de biofilme sobre sua superfície, dificultando o tratamento da periimplantite. Diversos métodos de limpeza da superfície do implante têm sido descritos, porém podem danificar sua superfície ou gerar resistência a longo prazo. A terapia fotodinâmica (PDT) surge como uma opção viável e de baixo custo para o tratamento da periimplantite. O objetivo deste estudo in vitro foi analisar a descontaminação bacteriana da superfície de implantes por meio da terapia fotodinâmica. 60 implantes dentários (TiUnite Nobel) foram igualmente divididos (n=10) em 4 grupos e 2 subgrupos. Em G1 não houve descontaminação (controle negativo), enquanto em G2 realizou-se a descontaminação pelo método tradicional com gluconato de clorexidina a 0,12% (controle positivo). G3 (PDT laser+corante) e G4 (sem corante) foram divididos em dois subgrupos cada, sendo que em G3a e G4a utilizou-se a PDT por 3 minutos, G3b e G4b por 5 minutos. Após 5 minutos em contato com o corante azul de metileno a 0,01% (G3), os implantes foram irradiados (G3 e G4) com laser diodo de baixa potência (AsGaAl, 660 nm, 30 mW) por 3 ou 5 minutos (7,2 e 12 J). Após diluições seriadas, os meios de cultura foram mantidos em atmosfera de anaerobiose por uma semana, e então realizada a contagem das unidades formadoras de colônias para cada grupo. Os testes estatísticos de Kruskal-Wallis e Mann-Whitney mostraram haver diferença significante (p<0,001) entre G1 e os demais grupos, bem como G4 comparado com G2 e G3. Melhores resultados de descontaminação foram obtidos para G2 e G3, sem diferença estatisticamente significante entre si. Os resultados obtidos neste estudo sugerem que a terapia fotodinâmica pode ser considerada um método eficaz para redução bacteriana em superfícies de implantes e que somente a irradiação laser, sem a associação do corante, foi menos eficiente (p<0,001) que a PDT. / If periimplantitis lesions are not properly treated, they can lead to bone resorption and loss of the implant. Implants with rough surface present better results and anchorage, however, they can facilitate biofilm formation on their surface, making the treatment of periimplantitis more difficult. Several surface debridement methods have been reported, however, some of them can injury the implant surface or create bacterial resistance in a long term followup. The photodynamic therapy (PDT) is a viable and low-cost option for treatment of periimplantitis. The aim of this in vitro study was to analyze the decontamination of implant surfaces by means of photodynamic therapy. 60 dental implants (TiUnite Nobel) were equally distributed (n=10) into 4 groups and 2 subgroups. At G1 group there was no decontamination (negative control), while in G2 the decontamination was made through the conventional method with chlorhexidine gluconate 0.12% (positive control). G3 (PDT laser+dye) and G4 (without dye) were divided in two subgroups each; while in G3a and G4a PDT was carried out for 3 minutes, G3b and G4b, was for 5 minutes. After five minutes in contact with methylene blue 0,01% dye (G3), the implants were irradiated (G3 and G4) with a diode low-power laser (AsGaAl, 660 nm, 30 mW) for 3 or 5 minutes (7.2 and 12J). After the dilutions, the culture media were kept in anaerobiosis atmosphere for one week, and then the counting of bacteria colonies was done for each group. The statistical tests of Kruskal-Wallis and Mann-Whitney showed significant difference (p<0,001) between G1 and other groups, as well as G4 compared with G2 and G3. Better results of decontamination were obtained in G2 and G3, with no statistical significance between them. The results of this study suggest that the photodynamic therapy can be considered an efficient method of bacteria reduction of implants surfaces, and only the laser irradiation, without dye association, was less efficient (p<0,001) than PDT.

A peri-implantite acomete um número crescente de indivíduos e os protocolos de tratamento objetivam descontaminar as superfícies dos implantes e torná-las novamente osseointegráveis. Porém, ainda não foi estabelecido um padrão ouro de tratamento para peri-implantite. Este estudo testa o poder de descontaminação do laser em baixa intensidade (LBI), da terapia fotodinâmica (PDT) e do azul de toluidina O (TBO). Sobre discos de titânio de 1,5 mm de espessura e 4,0 mm de diâmetro de superfícies lisas ou rugosas foi permitida a deposição natural de biofilme microbiano por 7 dias após os quais os discos foram divididos em grupos experimentais (15 discos por grupo), de acordo com o método de descontaminação: grupo LBI (laser de InGaAlP de 660 nm, 30 mW, 45 J/cm2 no modo continuo por 30 s); grupo PDT; grupo TBO (aplicação de TBO por 60 s); grupo controle positivo (C) sem tratamento e grupo controle negativo (NC) estéril. Os discos foram implantados em tecido conjuntivo subcutâneo de ratos e, após 7, 28 e 84 dias, foram obtidas 5 biópsias de cada grupo para análise em microscopia óptica. Implantes lisos e rugosos não diferiram com relação ao grau de fibrosamento e severidade do infiltrado inflamatório, mas a área do tecido reacional perimaterial foi maior nos rugosos (2,6 ± 3,7 x 106 µm2) do que nos lisos (1,9 ± 2,6 x 106 µm2). O grupo C foi o que apresentou menor grau de fibrosamento do tecido reacional (1), mas somente houve diferença estatisticamente significante (p = 0,0230) entre os grupos C e NC. A severidade do infiltrado inflamatório somente diferiu significantemente entre os grupos aos 7 dias, quando o grupo NC apresentou o menor escore (2) em comparação aos demais grupos (3). Com relação à área do tecido reacional perimaterial, só houve diferenças entre os grupos aos 7 dias, quando o grupo C apresentou maior área que os demais grupos (9,11 ± 2,10 x 106 µm2), porém, sem diferença estatisticamente significante em comparação aos grupos LBI e TBO. A área apresentada pelo grupo PDT (4,34 ± 1,49 x 106 µm2) só foi inferior ao grupo NC (0,65 ± 0,23 x 106 µm2). A espessura do tecido reacional não confirmou a diferença entre os discos de superfície lisa e os de superfície rugosa (p = 0,2801), mas confirmou todas as demais comparações relativas à área, sendo que o grupo NC apresentou menor espessura que os demais somente aos 7 dias. O grupo NC apresentou menor espessura de tecido reacional do que os demais grupos, mas essa diferença foi estatisticamente significante somente aos 7 dias. Os demais grupos não diferiram entre si quanto a esse parâmetro. Concluiu-se que implantes rugosos ou lisos contaminados por biofilme microbiano e tratados com LBI, PDT e TBO não diferem entre si quanto aos parâmetros inflamatórios teciduais, parecendo haver leve superioridade da PDT sobre os demais tratamentos apenas no período mais precoce de observação. Porém, com o passar do tempo, todos os tratamentos se equiparam a implantes estéreis quanto à reação tecidual perimaterial. / The peri-implantitis is a disease that is increasing in a number of individuals and the protocols of treatment has intended to decontaminate the implant surfaces and makes this biocompatible again. However, until this moment, a gold standard for peri-implantitis treatment was not established. The present study tests the power of decontamination of low intensity laser (LBI), photodynamic therapy (PDT) and toluidine blue O (TBO). The natural deposition of microbian biofilm was allowed on titanium discs with 1,5 mm of thickness and 4,0 mm of diameter and smooth and grooved surfaces during 7 days when the discs were separated in experimental groups (15 discs each group), in accordance with the decontamination method: LBI group (decontamination with InGaAlP laser, 660 nm, 30 mW, 45 J/cm2 in continuous way during 30 s); PDT group; TBO group (application of TBO during 60 s); controlled positive group (C) without any kind of treatment and controlled negative group (NC), sterile. The discs had been implanted in rats subcutaneous connective tissue and, after 7, 28 and 84 days, had been gotten 5 biopsies from each group for histology processing. Smooth and grooved implants did not differ on fibrosis grade and severity of the inflammatory infiltrate, however the perimaterial reaction tissue area was bigger on grooved implants (2,6 ± 3,7 x 106 µm2) that on smooth implants (1,9 ± 2,6 x 106 µm2). The C group was the one that showed the smallest reaction tissue fibrosis grade (1), but only was significant statistical difference (p = 0,0230) between C and NC groups. The severity of inflammatory infiltrate only significant differed between the groups on 7 days, when the NC group showed the smallest score (2) in comparison to the others groups (3). In relation to the perimaterial reaction tissue area, only were differences between the groups on 7 days, when C group showed bigger area than the others (9,11 ± 2,10 x 106 µm2), nevertheless, without significant statistical difference in Comparison to LBI and TBO groups. The area presented by PDT group (4,34 ± 1,49 x 106 µm2) only was inferior to NC group (0,65 ± 0,23 x 106 µm2). The reaction tissue thickness did not confirmed the difference between smooth and grooved surfaces discs (p = 0,2801), however it confirmed all the comparisons related to the area parameter, where NC group showed smaller thickness than the others only on 7 days. NC group showed smaller thickness than the others, but this difference was statistical significant only on 7 days. The other groups did not differ among them in this parameter. It was concluded that grooved and smooth implants contaminated by a microbian biofilm ant treated with LBI, PDT and TBO did not differed among them in relation to tissue inflammatory parameters, seems that is a light superiority of PDT in relation to the others only in the earliest period of observation. Nevertheless, with the time, all the treatments were equally to sterile implants in relation to perimaterial reaction tissue.

A colonização por microrganismos no sulco periimplantar ocorre muito precocemente, logo após a cirurgia de instalação dos implantes. Portanto, faz-se necessário um ótimo controle de higienização, que muitas vezes não ocorre durante as primeiras semanas, devido ao receio por parte do paciente em traumatizar a área cirúrgica. A terapia fotodinâmica ou PDT (Photodynamic Therapy) torna-se como uma alternativa de solucionar ou minimizar este problema, já que danifica ou destrói as células bacterianas, sem provocar formação de cepas resistentes ao procedimento. Com este intuito, o projeto foi proposto a fim de avaliar o efeito da terapia fotodinâmica na microbiota do sulco periimplantar. Após triagem (critérios de inclusão: normorreativos, com espaço intercalar superior, sem histórico de doença periodontal grave), 14 pacientes foram selecionados e reabilitados com implantes Standard Plus (Straumann® Dental Implant System), divididos em dois grupos, um grupo controle (GC) e um grupo submetido à terapia fotodinâmica (GPDT), cujo protocolo foi: irradiação contínua de 120J/cm2 de densidade de energia, numa potência de 40mW, associada ao corante azul de metileno a 0,005%. As aplicações foram realizadas no dia da instalação do implante, após 15, 30 e 45 dias. As coletas microbiológicas foram efetuadas no pós-cirúrgico imediato e na 6ª semana, nos dois grupos, utilizando cones de papel estéril. No GPDT, outras duas coletas foram realizadas após aplicação da terapia no dia da cirurgia e após 45 dias. Todo material coletado passou por diluições seriadas, semeado em meios de cultura e incubados em anaeróbiose para posterior contagem do número de unidades formadoras de colônias totais (UFCt) e pigmentadas de preto (UFCp). Os testes estatísticos aplicados foram os de Wilcoxon e MannWhitney. O número de UFCt e UFCp do pós-cirúrgico imediato para 6ª semana apresentou aumento, estatisticamente significante, nos dois grupos. No comparativo entre grupos não houve diferença, estatisticamente significante, entre a diferença do número de UFCt e UFCp do pós-cirúrgico imediato para 6ª semana. Quanto à eficiência da PDT, os resultados mostraram que houve uma redução, estatisticamente significante, tanto para as UFCt como UFCp nos dois momentos aplicados. Tendo como referência a mediana, a redução foi aproximadamente de 80% e 50% para as UFCt no pós-cirúrgico imediato e na 6ª semana, respectivamente. Para as UFCp, os valores foram de 100% e 90%. Conclusão: A terapia fotodinâmica é eficiente para redução das UFCt e UFCp, presentes no sulco periimplantar, durante a osseointegração. No entanto, essa terapia não impede a recolonização, nem o crescimento bacteriano ao longo do tempo. / The colonization by microorganisms in the peri-implant sulcus happens very early, right after the surgery to implant placement is finished. Therefore, a great hygienization control is required, such control does not occur in the first weeks due to the patients fear in traumatizing the surgical area. The photodynamic therapy (PDT) becomes an alternative to solve or to minimize such problem, since it damages or destroys the bacterial cells, without causing the formation of strains, resistant to the procedure. This project was proposed in order to evaluate the photodynamic therapy in the microbiota of the peri-implant sulcus. After the selection of patients (criteria: normoreactive patients, presenting intercalate superior space, with no history or signs of advanced aggressive periodontitis), 14 patients were seletected and rehabilitated via Standard Plus implants (Straumann® Dental Implant System), divided into two groups, a control group (GC) and a group subjected to the photodynamic therapy (GPDT), whose protocol was: continuous irradiation of 120J/cm2 of energy density, in 40mW of potency, associated to the Methylene blue dye at 0,005%. The applications were made in the implant placement day, after 15, 30 and 45 days. The microbiological collections were made in the immediate postoperative and in the 6th week, in both groups, by means of sterile paper points. In the GPDT, two other collections were made, one after the therapy application in the surgery day and one after 45 days. All the material collected passed through serial dilutions, plated in culture media and incubated in anaerobiosis to later counting of the total numbers of total colony-forming units (CFUt) and the numbers of black pigmented colony-forming units (CFUp). The statistical tests applied were the Wilcoxon and Mann-Whitney. The numbers of CFUt and CFUp in the immediate postoperative and in the 6th week, showed significant increase statistically in both groups. Comparing both groups, there was no statistically significant difference between the difference of the number of CFUt and CFUp in the immediate postoperative and in the 6th week. Regarding the PDT efficiency, the results showed a reduction, statistically significant, for CFUt and CFUp, in both application moments. Considering the median as a reference, the reduction was about 80% and 50% of CFUt in the immediate postoperative and in the 6th week, respectively. To CFUp, the values were 100% and 90%. Conclusion: the photodynamic therapy is efficient to CFUt and CFUp reduction, existent in the peri-implant sulcus, during the osseointegration. However, this therapy does not prevent the recolonization, neither the bacterial increasing over time.

O uso de plantas aromáticas ricas em óleos essenciais (OE) como agentes saneantes ou conservantes remonta às civilizações antigas. Nos dias atuais, o aumento nos surtos de infecções em hospitais e creches, bem como da resistência bacteriana, aumentou também a demanda por desinfetantes. Os OE\'s são reconhecidos por sua atividade antimicrobiana, mas a maioria dos estudos foi realizada na fase líquida. Buscando aproveitar a característica de alta volatilidade dos OE´s, desenvolvemos uma metodologia para a avaliação da atividade antimicrobiana na fase vapor. Nesse sentido, utilizamos o OE extraído de Hesperozygis myrtoides (St.Hil. ex Benth.) Epling (Lamiaceae), uma espécie nativa com ocorrência nos estados do sudeste do Brasil. A planta foi coletada em Campos do Jordão e o óleo teve um rendimento médio de 1,99% (m/m), sendo os componentes majoritários pulegona (48,8%) e isomentona (16,2%). A atividade antimicrobiana foi comparada na fase líquida, pelo método da microdiluição em placa, com a fase vapor, pelo método da placa invertida modificado. Os resultados indicaram uma atividade mais potente para a fase vapor do que na fase líquida. Staphylococcus aureus apresentou CIM de 0,392 mg. L-1 na fase vapor e 19 mg. L-1 na líquida, já para Candida albicans foi 0,833 mg. L-1 , na fase vapor e 94,4 mg. L-1 na fase líquida. Entretanto, para Escherichia coli, Pseudomonas aeruginosa, Bacilus subtillis e Aspergillus brasiliensis os valores da CIM, em ambas as fases, foram acima de 100 mg. L-1, sendo então considerado inativo. A atividade antimicrobiana na fase vapor é mais intensa devido aos OE´s se ligarem diretamente ao microrganismo sem a interferência do solvente. A toxicidade do OE foi avaliada frente a células tumorais humanas de mama (MCF-7) e próstata (CP-3) e em células de fibroblastos murinos normais (BALB/3T3) e indicaram uma DL50 superior a 2.014 mg.Kg-1, podendo ser considerado seguro. A atividade antimicrobiana associada à baixa toxicidade é um forte indicativo que este OE pode ser utilizado para descontaminação ambiental na fase vapor, inclusive em ambientes habitados. / Aromatic plants rich in essential oils (EO) have been used as sanitizing agents or preservatives since early civilizations. Nowadays, the increase in infectious outbreaks in hospitals and nurseries, as well as the bacterial resistance has also increased the demand for disinfectants. EO\'s are known for their antimicrobial activity, but most reports is in the liquid phase. Due to the EO high volatility, we have developed a methodology for evaluating the antimicrobial activity in the vapor phase. In this sense, we use the Hesperozygis myrtoides (St.Hil. Ex Benth.) Epling (Lamiaceae) EO, a native species occurring in southeastern Brazil. The plant was collected in Campos do Jordão (SP) and the oil had an average yield of 1.99% (m/m) and as major components pulegone (48.8%) and isomenthone (16.2%). Antimicrobial activity was compared in the liquid phase, microdilution method, with the vapor phase, modified inverted plate method. The results indicated that the vapor phase was a more potent than the liquid. Staphylococcus aureus afforded MIC 0.392 mg. L-1 for the vapor phase and 19 mg. L-1 for the liquid phase, while for Candida albicans it was 0.833 mg. L-1 for the vapor and 94.4 mg. L-1 for the liquid. However, Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Aspergillus brasiliensis had in both phases MIC\'s higher than 100 mg. L-1, considered then inactive. The vapor phase antimicrobial activity is more intense because the EO are free to directly bind with the microorganism without the solvent interference. Toxicity was evaluated against human breast tumor cells (MCF-7) and prostate cancer (PC-3) and with normal murine fibroblast cells (BALB/3T3) indicating a DL50 higher 2,014 mg.Kg-1, and it was considered safe. The antimicrobial activity associated with the low toxicity is a strong indication that this EO vapors can be used for environmental decontamination, even in inhabited places.

Yip, Ho-yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 181-201). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Contents --- p.vi / List of Figures --- p.x / List of Tables --- p.xvii / Abbreviations --- p.xix / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Polycyclic aromatic hydrocarbons (PAHs) --- p.1 / Chapter 1.1.1 --- Characteristics of PAHs --- p.1 / Chapter 1.1.2 --- Sources of PAHs --- p.2 / Chapter 1.1.3 --- Environmental fates of PAHs --- p.3 / Chapter 1.1.4 --- Effects of PAHs on living organisms --- p.5 / Chapter 1.1.4.1 --- General effects --- p.5 / Chapter 1.1.4.2 --- Effects on plants --- p.6 / Chapter 1.1.4.3 --- Effects on invertebrates --- p.7 / Chapter 1.1.4.4 --- Effects on fishes --- p.7 / Chapter 1.1.4.5 --- Effects on reptiles and amphibians --- p.8 / Chapter 1.1.4.6 --- Effects on birds --- p.9 / Chapter 1.1.4.7 --- Effects on mammals --- p.9 / Chapter 1.2 --- PAH contamination in Hong Kong --- p.10 / Chapter 1.3 --- Treatments of PAH contamination --- p.12 / Chapter 1.3.1 --- Physical treatments --- p.12 / Chapter 1.3.2 --- Chemical treatments --- p.13 / Chapter 1.3.3 --- Biological treatments --- p.14 / Chapter 1.4 --- Advanced oxidation processes (AOPs) --- p.16 / Chapter 1.5 --- Summary --- p.24 / Chapter 2. --- Objectives --- p.27 / Chapter 3. --- Materials and Methods --- p.28 / Chapter 3.1 --- Chemicals --- p.28 / Chapter 3.2 --- Photocatalytic reactor --- p.30 / Chapter 3.3 --- Determination of PAHs concentrations --- p.30 / Chapter 3.3.1 --- Extraction of PAHs --- p.30 / Chapter 3.3.2 --- Quantification of PAHs --- p.32 / Chapter 3.4 --- Optimization of physico-chemical conditions for PCO --- p.37 / Chapter 3.4.1 --- Determination of the reaction time for optimization of PCO --- p.37 / Chapter 3.4.2 --- Effect of titanium dioxide (Ti02) concentration and light intensity --- p.38 / Chapter 3.4.3 --- Effect of initial pH and hydrogen peroxide (H2O2) concentration --- p.38 / Chapter 3.4.4 --- Effect of initial PAHs concentration --- p.39 / Chapter 3.5 --- Toxicity analysis --- p.39 / Chapter 3.5.1 --- Microtox® test for acute toxicity --- p.39 / Chapter 3.5.2 --- Mutatox® test for genotoxicity --- p.42 / Chapter 3.6 --- Determination of total organic carbon (TOC) removal in optimized PCO --- p.43 / Chapter 3.7 --- Determination of degradation pathways --- p.43 / Chapter 3.7.1 --- Extraction of intermediates and/or degradation products --- p.45 / Chapter 3.7.2 --- Identification of intermediates and/or degradation products --- p.45 / Chapter 4. --- Results --- p.49 / Chapter 4.1 --- Determination of PAHs concentrations --- p.49 / Chapter 4.2 --- Optimization of extraction method --- p.49 / Chapter 4.3 --- Optimization of physico-chemical conditions for PCO --- p.49 / Chapter 4.3.1 --- Determination of the reaction time for optimization of PCO --- p.49 / Chapter 4.3.2 --- Effect of Ti02 concentration and light intensity --- p.60 / Chapter 4.3.3 --- Effect of initial pH --- p.88 / Chapter 4.3.4 --- Effect of initial H2O2 concentration --- p.99 / Chapter 4.3.5 --- Effect of initial PAHs concentration --- p.104 / Chapter 4.3.6 --- Improvements on removal efficiency (RE) after optimization --- p.113 / Chapter 4.4 --- Toxicity analysis --- p.122 / Chapter 4.4.1 --- Microtox® test for acute toxicity --- p.122 / Chapter 4.4.2 --- Mutatox® test for genotoxicity --- p.122 / Chapter 4.5 --- Determination of TOC removal in optimized PCO --- p.129 / Chapter 4.6 --- Determination of degradation pathways --- p.129 / Chapter 5. --- Discussion --- p.150 / Chapter 5.1 --- Determination of PAHs concentrations --- p.150 / Chapter 5.2 --- Optimization of extraction method --- p.150 / Chapter 5.3 --- Optimization of physico-chemical conditions for PCO --- p.151 / Chapter 5.3.1 --- Determination of the reaction time for optimization of PCO --- p.151 / Chapter 5.3.2 --- Effects of Ti02 concentration and light intensity --- p.152 / Chapter 5.3.3 --- Effects of initial pH --- p.160 / Chapter 5.3.4 --- Effects of initial H202 concentration --- p.163 / Chapter 5.3.5 --- Effects of initial PAHs concentration --- p.165 / Chapter 5.3.6 --- Improvements on RE after optimization --- p.167 / Chapter 5.4 --- Toxicity analysis --- p.169 / Chapter 5.4.1 --- Microtox® test for acute toxicity --- p.169 / Chapter 5.4.2 --- Mutatox® test for genotoxicity --- p.170 / Chapter 5.5 --- Determination of TOC removal in optimized PCO --- p.171 / Chapter 5.6 --- Determination of detoxification pathways --- p.172 / Chapter 6. --- Conclusion --- p.177 / Chapter 7. --- References --- p.181 / Chapter 8. --- Appendix I --- p.202

Orientador: Cecília Laluce / Resumo: A contaminação bacteriana nas destilarias de etanol é um problema crônico que afeta o rendimento, na medida em que esses microrganismos competem pelo substrato a ser convertido em álcool pelas leveduras e liberam produtos indesejados no meio. A adição de ácido sulfúrico ao inóculo é a prática mais utilizada no controle dessas bactérias, contudo é uma substância de baixa eficácia, que também afeta a levedura. Antibacterianos utilizados complementarmente devem levar em conta a seletividade; o espectro de ação; e ainda restrições em fermentações que utilizam o excedente de levedura para ração animal. Nesse contexto, esse trabalho se propôs a estudar diversos biocidas, com base na literatura e desempenho em outras áreas. Foram realizadas fermentações por bateladas em frascos agitados em condições operacionais padrão (pH, temperatura, concentração de açúcares) com recuperação de células ao final de cada ciclo, reproduzindo o processo industrial. Os inóculos contendo leveduras e bactérias foram tratados com os seguintes produtos: peróxido de hidrogênio aditivado com prata; cloro oxigenado; triclorocarbanilida; cloreto de benzalcônio; digluconato de clorexidina; maitenina; salinomicina, e agentes quelantes EDTA e HEDTA, além dos produtos referência (beta ácido de lúpulo e monensina). Ao final das fermentações foram analisadas a população de bactérias, a viabilidade da levedura, e os teores de ácido lático e etanol. O biocida a base de peróxido, na dose 1.000 ppm não mostrou a mesma ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Bacterial contamination in ethanol distilleries is a chronic problem that affecting the yield, once these microorganisms compete for the substrate to be converted to alcohol by yeast, as well as release undesired products in the medium. The addition of sulfuric acid to the inoculum is the most used practice to control such bacteria, but is a substance of low efficacy, which also affects the yeast. Antibacterial used in addition should take into account the selectivity; spectrum; and also restriction in fermentation that uses yeast surplus for animal feed. In this context, this work proposes to study various biocides, based on the literature and performance in other areas. Batch fermentations were performed in shake flasks under standard operational conditions (pH, temperature, sugar concentration) with a recovery of cells at the end of each cycle, reproducing the industrial process. The inoculum containing yeast and bacteria were treated with hydrogen peroxide plus silver; oxygenated chlorine; trichlorocarbanilide plus benzalkonium chloride; chlorhexidine digluconate; maytenin; salinomycin, and chelating agents EDTA and HEDTA, indeed the reference products (beta hops acid and monensin). At the end of fermentations were performed analysis of population of bacteria, yeast viability and lactic acid and ethanol concentration. The peroxide-based biocide in the dose 1000 ppm did not showed the same efficacy recorded in preliminary tests in vitro, which showed a MIC of 200 ppm for l... (Complete abstract click electronic access below) / Doutor

Under lagring och transport av textila varor från Asien kan risken för mögelangrepp vara stor, något som sedan vid uppackning kan vara skadligt för hälsan. Situationen så som det ser ut idag kan medföra stora problem och kostnader hos textilföretag och att hitta möjliga åtgärder för att förebygga skador är därför av stort intresse. För att kartlägga problemen med mögelangrepp på textila material har både informationssökning och praktiskt arbete genomförts. Mögeltillväxt sker då det är gynnsamma betingelser med hänsyn till klimat, näring och syretillgång. För att mögeltillväxt inte ska angripa textila varor finns en rad förebyggande åtgärder som kan vidtas, åtgärder som alla handlar om att göra förutsättningarna på ett eller annat sätt ogynnsamma. Olika textila material angrips olika lätt av mögel men genom att hålla varorna rena från smuts samt ha kontroll över den relativa fuktigheten kan varorna klara sig en längre tid utan att bli angripna. Reglering av den relativa fuktigheten kan göras genom användning av avfuktare eller diverse fuktabsorbenter. Även användning av biocider på varorna i samband med packning kan hämma mögeltillväxten. Textila materials benägenhet till att mögla beror på en rad faktorer och efter den mögelodling som satts igång kunde det konstateras att bomull är det material som lättast angrips. Vid uppackning av mögelskadade varor bör försiktighetsprincipen tillämpas och för att rädda de varor som angripits kan olika saneringsmetoder användas, där olika metoder lämpar sig för olika material. Dock har det visat sig, i studier som gjorts på byggmaterial, att vissa saneringsmetoder medfört en kvarvarande eller ökad toxinhalt efter sanering vilket således innebär att sanering inte alltid gör varorna brukbara. During storage and transport of textiles from Asia, the risk of mold growth is high. When unpacking the affected textiles the mold can be harmful to the health of the workers. Today, mold growth in textiles results in major problems and costs for the textile companies. Therefore, it is of great interest for the companies to find possible measures to prevent damages due to mold growth. In order to fully understand the problems with mold on the textiles, both a literature survey and practical work has been done. Mold growth occurs when there are favorable conditions with regard to climate, nutrients and oxygen. There are some preventative measures that can be taken to deter mold growth, which are all about making the conditions, in one way or another, unfavorable.The ease in which different textiles are attacked by mold varies greatly, but by keeping them clean and controlling the relative humidity, the textiles can last a long time without being attacked. The relative humidity can be controlled by using a dehumidifier or various moisture absorbers. Also, using biocides on fabrics during packing may inhibit mold growth. The propensity of mold growth on textiles depends on several factors. The mold experimentsrevealed that cotton is the most easily attacked material. When unpacking the mold damaged goods, the precautionary principle should be used and to save the textiles that have been attacked, different decontamination methods can be used. Different methods are useful for different materials. However, it has been found in studies of construction materials that some decontamination methods lead to residual or increased toxin levels after the decontamination. This means the decontamination does not always make the products usable. / Program: Textilingenjörsutbildningen