Liquens são organismos em simbiose, considerados indicadores biológicos e, assim como os biomarcadores de genotoxicidade, são amplamente empregados para avaliar a qualidade do ar em áreas urbanas. Desta forma, este estudo teve por objetivos analisar a comunidade liquênica na cidade de Porto Alegre, RS, através do mapeamento da micota liquenizada e comparar a influência de determinados poluentes nas estruturas morfofisiológicas de algumas espécies liquênicas e na atividade mutagênica e citotóxica do material particulado atmosférico. A comunidade liquênica foi analisada, a fim de verificar alterações na sua estrutura, e danos morfofisiológicos em duas espécies (Parmotrema tinctorum e Teloschistes exilis), pela ação de determinados poluentes. Foram analisadas 30 estações amostrais, distribuídas em 29 áreas da cidade, e uma de referência no Parque Estadual de Itapuã, RS. Foram empregados o método do elástico para mapear os liquens, o método dos transplantes para analisar a ação de alguns poluentes atmosféricos e o ensaio Salmonella/microssoma para avaliar a mutagenicidade e citotoxicidade dos extratos orgânicos do PM10. Foram registrados 144 táxons liquênicos. Alterações na estrutura da comunidade liquênica foram verificadas nas áreas analisadas. Concentrações de poluentes, incluindo HPAs, foram constatadas nas espécies expostas, além de danos morfofisiológicos. Atividade mutagênica também foi verificada nos primeiros meses de exposição dos liquens, bem como a presença de nitrocompostos no ar. Na avaliação geral da comunidade liquênica urbana, constatou-se que fatores, como tráfego veicular, variáveis climáticas e topografia das estações amostradas, podem ter contribuído para os resultados encontrados. A utilização conjunta entre os bioindicadores e os biomarcadoress de mutagênese proporcionou a avaliação da qualidade do ar e o diagnóstico da presença de compostos agressivos ao meio ambiente. O emprego dos liquens como indicadores de alterações em ambientes urbanos são recomendados, podendo servir como ferramenta para programas de monitoramento nas cidades. / Lichens are symbiotic organisms considered as biological indicators and like genotoxicity biomarkers, are widely used to evaluate air quality in urban areas. Thus, the present study aims to analyze the lichen community in Porto Alegre, RS, by mapping lichenized mycota and also aims to compare the influence of certain pollutants morphophysiological structures of some lichen species and in the mutagenic and cytototoxicity activity in atmospheric particulate matter. The lichen community was analyzed in order to verify structure alterations, in addition to morphophysiological damages in two species (Parmotrema tinctorum and Teloschistes exilis) caused by the action of specific pollutants. Thirty sample stations were analyzed, distributed into twenty-nine areas in the city and a reference area in the State Park of Itapuã, RS. The band rubber method was used for mapping lichens, the transplant methodology was used in order to analyze the action of some atmospheric pollutants and the Salmonella/microsome assay was used to evaluate mutagenicity and cytotoxicity of PM10 organic extracts. One hundred and forty-four lichen taxa were registered. Alterations in the structure of the lichen community were verified in the analyzed areas. Pollutant concentrations, including PAHs were observed in the exposed species, in addition to morphophysiological damages. Mutagenic activity was also verified in the first months of lichen exposure, as well as the presence of nitrocompounds in the air. A general evaluation of the urban lichen community verified that traffic flow, climate variables and topography of the sampled stations may have contributed to the results obtained. The use of both bioindicators and mutagenesis biomarkers provided an evaluation of air quality and helped to determine of the presence of environmentalaggressive compounds. The use of lichens as indicators of alterations in urban environments is recommended and may serve as a tool for monitoring programs in cities.

Liquens são organismos em simbiose, considerados indicadores biológicos e, assim como os biomarcadores de genotoxicidade, são amplamente empregados para avaliar a qualidade do ar em áreas urbanas. Desta forma, este estudo teve por objetivos analisar a comunidade liquênica na cidade de Porto Alegre, RS, através do mapeamento da micota liquenizada e comparar a influência de determinados poluentes nas estruturas morfofisiológicas de algumas espécies liquênicas e na atividade mutagênica e citotóxica do material particulado atmosférico. A comunidade liquênica foi analisada, a fim de verificar alterações na sua estrutura, e danos morfofisiológicos em duas espécies (Parmotrema tinctorum e Teloschistes exilis), pela ação de determinados poluentes. Foram analisadas 30 estações amostrais, distribuídas em 29 áreas da cidade, e uma de referência no Parque Estadual de Itapuã, RS. Foram empregados o método do elástico para mapear os liquens, o método dos transplantes para analisar a ação de alguns poluentes atmosféricos e o ensaio Salmonella/microssoma para avaliar a mutagenicidade e citotoxicidade dos extratos orgânicos do PM10. Foram registrados 144 táxons liquênicos. Alterações na estrutura da comunidade liquênica foram verificadas nas áreas analisadas. Concentrações de poluentes, incluindo HPAs, foram constatadas nas espécies expostas, além de danos morfofisiológicos. Atividade mutagênica também foi verificada nos primeiros meses de exposição dos liquens, bem como a presença de nitrocompostos no ar. Na avaliação geral da comunidade liquênica urbana, constatou-se que fatores, como tráfego veicular, variáveis climáticas e topografia das estações amostradas, podem ter contribuído para os resultados encontrados. A utilização conjunta entre os bioindicadores e os biomarcadoress de mutagênese proporcionou a avaliação da qualidade do ar e o diagnóstico da presença de compostos agressivos ao meio ambiente. O emprego dos liquens como indicadores de alterações em ambientes urbanos são recomendados, podendo servir como ferramenta para programas de monitoramento nas cidades. / Lichens are symbiotic organisms considered as biological indicators and like genotoxicity biomarkers, are widely used to evaluate air quality in urban areas. Thus, the present study aims to analyze the lichen community in Porto Alegre, RS, by mapping lichenized mycota and also aims to compare the influence of certain pollutants morphophysiological structures of some lichen species and in the mutagenic and cytototoxicity activity in atmospheric particulate matter. The lichen community was analyzed in order to verify structure alterations, in addition to morphophysiological damages in two species (Parmotrema tinctorum and Teloschistes exilis) caused by the action of specific pollutants. Thirty sample stations were analyzed, distributed into twenty-nine areas in the city and a reference area in the State Park of Itapuã, RS. The band rubber method was used for mapping lichens, the transplant methodology was used in order to analyze the action of some atmospheric pollutants and the Salmonella/microsome assay was used to evaluate mutagenicity and cytotoxicity of PM10 organic extracts. One hundred and forty-four lichen taxa were registered. Alterations in the structure of the lichen community were verified in the analyzed areas. Pollutant concentrations, including PAHs were observed in the exposed species, in addition to morphophysiological damages. Mutagenic activity was also verified in the first months of lichen exposure, as well as the presence of nitrocompounds in the air. A general evaluation of the urban lichen community verified that traffic flow, climate variables and topography of the sampled stations may have contributed to the results obtained. The use of both bioindicators and mutagenesis biomarkers provided an evaluation of air quality and helped to determine of the presence of environmentalaggressive compounds. The use of lichens as indicators of alterations in urban environments is recommended and may serve as a tool for monitoring programs in cities.

Liquens são organismos em simbiose, considerados indicadores biológicos e, assim como os biomarcadores de genotoxicidade, são amplamente empregados para avaliar a qualidade do ar em áreas urbanas. Desta forma, este estudo teve por objetivos analisar a comunidade liquênica na cidade de Porto Alegre, RS, através do mapeamento da micota liquenizada e comparar a influência de determinados poluentes nas estruturas morfofisiológicas de algumas espécies liquênicas e na atividade mutagênica e citotóxica do material particulado atmosférico. A comunidade liquênica foi analisada, a fim de verificar alterações na sua estrutura, e danos morfofisiológicos em duas espécies (Parmotrema tinctorum e Teloschistes exilis), pela ação de determinados poluentes. Foram analisadas 30 estações amostrais, distribuídas em 29 áreas da cidade, e uma de referência no Parque Estadual de Itapuã, RS. Foram empregados o método do elástico para mapear os liquens, o método dos transplantes para analisar a ação de alguns poluentes atmosféricos e o ensaio Salmonella/microssoma para avaliar a mutagenicidade e citotoxicidade dos extratos orgânicos do PM10. Foram registrados 144 táxons liquênicos. Alterações na estrutura da comunidade liquênica foram verificadas nas áreas analisadas. Concentrações de poluentes, incluindo HPAs, foram constatadas nas espécies expostas, além de danos morfofisiológicos. Atividade mutagênica também foi verificada nos primeiros meses de exposição dos liquens, bem como a presença de nitrocompostos no ar. Na avaliação geral da comunidade liquênica urbana, constatou-se que fatores, como tráfego veicular, variáveis climáticas e topografia das estações amostradas, podem ter contribuído para os resultados encontrados. A utilização conjunta entre os bioindicadores e os biomarcadoress de mutagênese proporcionou a avaliação da qualidade do ar e o diagnóstico da presença de compostos agressivos ao meio ambiente. O emprego dos liquens como indicadores de alterações em ambientes urbanos são recomendados, podendo servir como ferramenta para programas de monitoramento nas cidades. / Lichens are symbiotic organisms considered as biological indicators and like genotoxicity biomarkers, are widely used to evaluate air quality in urban areas. Thus, the present study aims to analyze the lichen community in Porto Alegre, RS, by mapping lichenized mycota and also aims to compare the influence of certain pollutants morphophysiological structures of some lichen species and in the mutagenic and cytototoxicity activity in atmospheric particulate matter. The lichen community was analyzed in order to verify structure alterations, in addition to morphophysiological damages in two species (Parmotrema tinctorum and Teloschistes exilis) caused by the action of specific pollutants. Thirty sample stations were analyzed, distributed into twenty-nine areas in the city and a reference area in the State Park of Itapuã, RS. The band rubber method was used for mapping lichens, the transplant methodology was used in order to analyze the action of some atmospheric pollutants and the Salmonella/microsome assay was used to evaluate mutagenicity and cytotoxicity of PM10 organic extracts. One hundred and forty-four lichen taxa were registered. Alterations in the structure of the lichen community were verified in the analyzed areas. Pollutant concentrations, including PAHs were observed in the exposed species, in addition to morphophysiological damages. Mutagenic activity was also verified in the first months of lichen exposure, as well as the presence of nitrocompounds in the air. A general evaluation of the urban lichen community verified that traffic flow, climate variables and topography of the sampled stations may have contributed to the results obtained. The use of both bioindicators and mutagenesis biomarkers provided an evaluation of air quality and helped to determine of the presence of environmentalaggressive compounds. The use of lichens as indicators of alterations in urban environments is recommended and may serve as a tool for monitoring programs in cities.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-05-23T12:59:30Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tese Josineide Braz - PPGEOC.2016.pdf: 4942673 bytes, checksum: 8c5e68ef53147158bd12d20be3d26ed6 (MD5) / Made available in DSpace on 2017-05-23T12:59:30Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tese Josineide Braz - PPGEOC.2016.pdf: 4942673 bytes, checksum: 8c5e68ef53147158bd12d20be3d26ed6 (MD5) Previous issue date: 2016-05-12 / A evolução sedimentológica e geoquímica da Bacia Hidrográfica do Rio Goiana (Pernambuco-Brasil) é abordada nesta pesquisa cobrindo cerca de 300 anos de sua história. Os resultados são suportados por análises em testemunhos de perfil de fundo realizado no médio estuário deste rio, a 10 km da foz. As determinações em sedimento total envolvem: granulometria, análises óxidos fundamentais/elementos traços, DRX, análises CNH, matéria orgânica, análises de hidrocarbonetos (HPAs), além de δ13C, δ15N, razão C/N e datações 210 Pb e 14C. Os resultados permitiram compartimentar o desenvolvimento sedimentar/geoquímico em 3 estágios: séculos XX-XXI, século XIX, séculos XVIII-XIX, sobrepondo-se sobre registros pré-antropocênicos. Os principais incidentes climatológicos (enchentes de 1899 e 2011) e grandes secas (1824-1825 e 1877-1879), mostraram assinaturas características sedimentares, mineralógicas e geoquímicas, notando-se ainda um registro de perturbação sedimentológica/geoquímica no início do século XVIII, supostamente resultante da reforma no porto local. A natureza desses registros é discutida também, com referência aos principais contaminantes químicos tóxicos (metais e HPAs). Constatou-se que as contaminações de Ni-Cr são crônicas nesta bacia, desde séculos atrás, e que as concentrações de Hg, embora abaixo dos limiares recomendados pela USEPA/CCME, mostram evidências de insuficiente complexação no sistema. A vegetação predominante na área desde o século XVIII é arbórea, e a expansão do cultivo de cana-deaçúcar não foi suficiente para afetar o padrão vigente de δ13C. As fontes dos HPAs para o estuário têm predomínio pirotécnico, derivado da combustão da biomassa, do carvão e, principalmente, de combustíveis fósseis. / Sedimentological and geochemical evolution of estuarine of the Goiana River (Pernambuco, Brazil) is presented in this research covering 300 years of the history. The results are supported by analysis in core sediments performed at the middle estuary, 10 km from the mouth. The determinations in the total sediment involves: particle size, oxides/trace elements analysis, XRD, CNH, organic matter – polycyclic aromatichydrocarbons (PAHs) analysis, δ13C and δ15N determinations, C/N ratios and 210Pb and 14C dating. The results allow to the segmentation of the sedimentary/geochemistry development in 3 stages: XX-XXI centuries, XIX century, and XVIII-XIX centuries, overlapping records of the Anthropocene. The main climatological events (floods: 1899 and 2011); severe droughts (1824-1825 and 1877-1879), showed characteristics sedimentary records, mineralogical and geochemical signatures, noting also a signaling of sedimentological/geochemistry disturbance at the beginning of the XVIII century, supposed from local harbor improvement. The nature of these registers is discussed also with reference to the main chemical contaminants with potential toxicity (metals and PAHs). Conclusively, the Ni-Cr contaminations are chronic in this basin since centuries ago, and more recent Hg concentrations also, although when these concentration are below the thresholds recommended by USEPA/CCME. These evidences points to insufficient complexation in the studied aquatic system. The predominant vegetation in the area since the XVIII century is of arboreal characteristic, but the expansion of sugarcane cultivation was not enough to affect the current pattern of δ13C. The main sources PAHs to the estuary are pyrogenic, predominantly derived from the combustion of biomass, coal and especially fossil fuels.

Tesis por compendio / [ES] La producción y consumo de plásticos derivados de petróleo ha crecido exponencialmente en las últimas décadas, impactando en la naturaleza y los seres vivos. Los envases alimentarios son considerados la principal fuente de contaminación por plásticos. Por ello, el estudio y desarrollo de nuevos materiales derivados de recursos renovables y biodegradables ha emergido como un nuevo campo de gran interés. La presente tesis doctoral se enfocó en el desarrollo y caracterización de biopolímeros de polihidroxialcanoato (PHA) derivados de subproductos industriales y de la fracción orgánica de aguas residuales municipales, los residuos biológicos municipales, sintetizados por cultivos microbianos mixtos y producidos mediante las tecnologías de electroestirado y mezclado en fundido. Los materiales resultantes fueron desarrollados para obtener monocapas y multicapas activas y de alta barrera a oxígeno para su uso en envases alimentarios basados en la Bioeconomía Circular. Para lograr los objetivos, esta tesis doctoral se ha dividido en tres bloques según la tecnología utilizada en la obtención de los materiales. El primer bloque consistió en la extracción de los PHAs derivados de residuos agro-industriales para su óptima utilización en los procesos de producción. Posteriormente, se realizó el procesado de los PHAs mediante la técnica de electroestirado, por la cual se obtuvieron fibras poliméricas que fueron tratadas térmicamente para formar films continuos y homogéneos. Estas monocapas presentaron buenas propiedades térmicas y mecánicas, así como alta barrera tanto a vapores como a gases. Además, las fibras fueron funcionalizadas con compuestos orgánicos presentes en aceites esenciales para proporcionarles una función antimicrobiana activa contra microorganismos trasmitidos por los alimentos. Por otro lado, se realizó el electroestirado de copolímeros de etileno-alcohol vinílico, un polímero sintético que se biodegrada en condiciones específicas y que posee alta barrera a oxígeno. Además, nanocristales de celulosa fueron añadidos al EVOH, para crear monocapas híbridas de alta barrera más sostenibles. En el segundo bloque, los materiales se procesaron mediante la técnica de mezclado en fundido. Para ello, los PHAs derivados de biomasa del primer bloque se mezclaron con PHAs comerciales, así como con cargas celulósicas para formar "compuestos verdes", en el que todos los materiales estaban basados en recursos renovables y biodegradables. Las mezclas mostraron buena miscibilidad y propiedades ópticas, una flexibilidad mejorada, así como propiedades de barrera similares a las del material de biopoliéster puro. Finalmente, en el tercer bloque, se produjeron sistemas multicapas utilizando mezclas de PHA desarrolladas ad-hoc, y materiales monocapa de PHA electroestirado del primer bloque. Estas estructuras multicapas se basaron en las propiedades adhesivas que poseen las fibras electroestiradas tras aplicarles el tratamiento térmico y en el uso de los revestimientos de CNCs como capas intermedias de barrera a oxígeno. Así, los sistemas multicapas desarrollados fueron totalmente compostables, con alta barrera a oxígeno, siendo potenciales candidatos para sustituir a los actuales envases alimentarios basados en materiales no renovables provenientes del petróleo. Por lo tanto, los materiales aquí desarrollados son tanto bioadhesivos muy prometedores que muestran propiedades antimicrobianas y de alta barrera, como capas exteriores con fines estructurales o para uso como films finos. Así, por laminación, estos materiales pueden dar lugar a films multicapas autoadhesivos, empleados tanto en envases rígidos, semirrígidos o flexibles. Estas estructuras son sostenibles y respetuosas con el medio ambiente y además son biodegradables mediante compostaje y, en algún caso, biodegradables en el medio ambiente. Asimismo, son potencialmente capaces de proporcionar una calidad y seguridad alimentaria comparables a las derivadas de fuentes petroquímicas. / [CA] La producció i el consum de plàstics derivats de petroli ha crescut exponencialment en les últimes dècades, impactant en la naturalesa i els éssers vius. Els envasos alimentaris són considerats la principal font de contaminació per plàstics. Per això, l'estudi i el desenvolupament de nous materials derivats de recursos renovables i biodegradables ha emergit com un nou camp de gran interès. Aquesta tesi doctoral es va enfocar en el desenvolupament i la caracterització de biopolímers de polihidroxialcanoat (PHA) derivats de subproductes industrials i de la fracció orgànica d'aigües residuals municipals, els residus biològics municipals, sintetitzats per cultius microbians mixtos i produïts mitjançant les tecnologies d'electroestirat i barrejat en fosa. Els materials resultants van ser desenvolupats per obtenir monocapes i multicapes actives i d'alta barrera a oxigen per utilitzar-los en envasos alimentaris basats en la Bioeconomia Circular. Per assolir els objectius, aquesta tesi doctoral s'ha dividit en tres blocs segons la tecnologia utilitzada per obtenir els materials. El primer bloc va consistir en l'extracció dels PHA derivats de residus agroindustrials per a la seva òptima utilització en els processos de producció. Posteriorment, es va realitzar el processament dels PHA mitjançant la tècnica d'electroestirat, per la qual es van obtenir fibres polimèriques que van ser tractades tèrmicament per formar films continus i homogenis. Aquestes monocapes van presentar bones propietats tèrmiques i mecàniques, així com alta barrera tant a vapors com a gasos. A més, les fibres van ser funcionalitzades amb compostos orgànics presents en olis essencials per proporcionar-los una funció antimicrobiana activa contra microorganismes transmesos pels aliments. D'altra banda, es va realitzar l'electroestirat de copolímers d'etilè-alcohol vinílic, un polímer sintètic que es biodegrada en condicions específiques i que té alta barrera a oxigen. A més, nanocristalls de cel·lulosa van ser afegits a l'EVOH, per crear monocapes híbrides d'alta barrera més sostenibles. Al segon bloc, els materials es van processar mitjançant la tècnica de barrejat en fosa. Per això, els PHAs derivats de biomassa del primer bloc es van barrejar amb PHAs comercials, així com amb càrregues cel·lulòsiques per formar "compostos verds", en què tots els materials estaven basats en recursos renovables i biodegradables. Les barreges van mostrar bona miscibilitat i propietats òptiques, una flexibilitat millorada, així com propietats de barrera similars a les del material de biopolièster pur. Finalment, al tercer bloc, es van produir sistemes multicapes utilitzant barreges de PHA desenvolupades ad-hoc, i materials monocapa de PHA electroestirat del primer bloc. Aquestes estructures multicapes es van basar en les propietats adhesives que tenen les fibres electroestirades després d'aplicar-los el tractament tèrmic i en l'ús dels revestiments de CNC com a capes intermèdies de barrera a oxigen. Així, els sistemes multicapes desenvolupats van ser totalment compostables, amb alta barrera a oxigen, sent potencials candidats per substituir els actuals envasos alimentaris basats en materials no renovables provinents del petroli. Per tant, els materials aquí desenvolupats són tant bioadhesius molt prometedors que mostren propietats antimicrobianes i d'alta barrera, com a capes exteriors amb fins estructurals o per a ús com a films fins. Així, per laminació, aquests materials poden donar lloc a films multicapes autoadhesius, emprats tant en envasos rígids, semirígids o flexibles. Aquestes estructures són sostenibles i respectuoses amb el medi ambient ia més són biodegradables mitjançant compostatge i, en algun cas, biodegradables al medi ambient. Així mateix, són potencialment capaços de proporcionar una qualitat i seguretat alimentària comparables a les derivades de fonts petroquímiques. / [EN] The production and consumption of petroleum derived plastics that are not biodegradable has grown exponentially in recent decades, with the consequent impact on nature and organisms. The food packaging sector is today considered the main source of plastic contamination. Therefore, the study and development of new materials derived from renewable and biodegradable resources has emerged as a new field of great scientific, social, economic and political interest. The current PhD thesis focused on the development and characterization of polyhydroxyalkanoate (PHA) biopolymers derived from agro-industrial by-products and from the organic fraction of municipal wastewater, the municipal biowaste, synthesized by mixed microbial cultures and produced by electrospinning and melt compounding technologies. The resultant materials were particularly developed to obtain high-oxygen-barrier active monolayers and multilayers for use in Circular Bioeconomy-based food packaging. In order to achieve the objectives, this PhD thesis has been divided into three blocks according to the technology used to obtain the materials. The first block consisted of the extraction of PHAs derived from agro-industrial waste for their optimal use in production processes. After this, the PHAs were then processed using the electrospinning technique, whereby polymeric fibers were obtained and thermally post-treated by an annealing process to form continuous and homogeneous films, also known as "biopapers". These monolayers showed good thermal and mechanical properties, as well as a high barrier to both vapors and gases. In addition, the fibers were functionalized with eugenol, an organic compound present in essential oils, to provide them with active antimicrobial function against foodborne microorganisms. On the other hand, the electrospinning of poly(ethylene-co-vinyl alcohol) copolymers, a synthetic polymer that is claimed to biodegrade under specific conditions and with high oxygen barrier, was performed. Cellulose nanocrystals were added to EVOH, to create high barrier more sustainable hybrid monolayers. In the second block, the materials were processed using the melt compounding technique. For this purpose, the biomass derived PHAs extracted in the first block were blended with commercial PHAs as well as with cellulosic fillers, in this case rice husk flour, in order to form "green composites", where all the materials were based on renewable and biodegradable resources. After film formation by hot pressing, the blends showed excellent miscibility and optical properties, improved flexibility, as well as barrier properties similar to the neat biopolyester material. Finally, in the third block, multilayer systems were produced using ad-hoc developed PHA blends, and PHA electrospun monolayer materials developed in the first block. They were based on the adhesive properties of the electrospun fibers after thermal treatment, which allowed the elimination of synthetic adhesive substances normally used in the industry, and on the use of the CNCs coatings as oxygen barrier interlayers. Thus, the multilayer systems developed were fully compostable, with high oxygen barrier, being potential candidates to replace current food packaging based on non-renewable petroleum-based materials. Therefore, the materials developed herein are very promising bioadhesives showing antimicrobial and high barrier properties, as well as outer layers for structural or thin film purposes. Thus, by lamination, these materials can result in self-standing multilayer films, which can be used in rigid or semirigid packaging as well as in flexible packaging. They are sustainable and environmentally friendly, as they are made from renewable sources or waste, and are biodegradable by composting, and, in some case, even biodegradable in the environment. Furthermore, they are potentially capable of providing comparable quality and food safety to those currently marketed from petrochemical sources. / Meléndez Rodríguez, B. (2022). Development and Characterization of Monolayers and Multilayers Based on Biodegradable Materials Derived from Waste and By-products of Interest in Food Packaging [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/184651 / TESIS / Compendio

El presente trabajo tiene por objetivo estudiar las aplicaciones de los nanocristales o ¿nanowhiskers¿ extraídos mediante hidrólisis ácida de celulosa bacteriana (BCNW) para el desarrollo de materiales poliméricos y biopoliméricos con propiedades mejoradas para su uso en aplicaciones de envasado de alimentos. En primer lugar se estudió y optimizó el proceso de extracción de BCNW. Se desarrolló un procedimiento de extracción con ácido sulfúrico, que permitió obtener nanocristales con elevada relación de aspecto y cristalinidad y al mismo tiempo, un elevado rendimiento de extracción. Este procedimiento comprende una posterior etapa de neutralización que resultó ser necesaria para garantizar la estabilidad térmica de los nanocristales. El siguiente paso consistió en la formulación de materiales nanocompuestos con propiedades mejoradas incorporando BCNW en diferentes matrices plásticas, en concreto copolímeros de etileno-alcohol vinílico (EVOH), ácido poliláctico (PLA) y polihidroxialcanoatos (PHAs). Mediante las técnicas de electroestirado y estirado por soplado se generaron fibras híbridas de EVOH y PLA con BCNW. La incorporación de BCNW en las disoluciones empleadas para producir fibras modificó significativamente sus propiedades (viscosidad, tensión superficial y conductividad) y por tanto, la morfología de las fibras se vio afectada. Además, se generaron fibras con propiedades antimicrobianas mediante la incorporación de aditivos, maximizando el efecto antimicrobiano con la adición de sustancias de carácter hidrofílico. Seguidamente, se produjeron nanocompuestos por mezclado en fundido y se desarrollaron técnicas de pre-incorporación de BCNW para evitar la aglomeración de los mismos no sólo en matrices hidrofílicas como el EVOH, sino también en matrices hidrofóbicas como el PLA. La dispersión óptima de BCNW resultó en una mejora de las propiedades mecánicas y de barrera de los nanocompuestos. También se estudió la modificación de la superficie de los nanocristales mediante copolimerización con poli(glicidil metacrilato) para mejorar la compatibilidad de BCNW con una matriz hidrofóbica como el PLA. Se incluyen además los primeros resultados obtenidos en cuanto a la producción de nanobiocompuestos sintetizados por microorganismos, que consisten en PHAs con diferentes contenidos de hidroxivalerato reforzados con BCNW. Por último, se desarrollaron películas con propiedades de alta barrera basadas en películas de BCNW recubiertas con capas hidrofóbicas. El recubrimiento mediante la deposición de fibras por electrospinning seguido de homogeneización por calentamiento garantizó una buena adhesión entre las diferentes capas, protegiendo así las películas de BCNW del efecto negativo de la humedad. / Martínez Sanz, M. (2013). Bacterial cellulose nanowhiskers to enhance the properties of plastics and bioplastics of interest in food packaging [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/30312 / TESIS / Premios Extraordinarios de tesis doctorales

Lead is a known toxin, with the ability to accumulate in the human body from as early as fetal development. Lead exposure is known to cause a myriad of health effects which are more prominent among children. Health effects upon exposure can range from renal and heart disease or potentially cancer in adults to neurotoxicity in children. The continued presence of old lead service lines and plumbing in distribution systems as well as lead-containing solders and brass fixtures in homes may contribute lead to drinking water. Recent studies have highlighted the importance of a predictor known as the chloride-to-sulfate mass ratio (CSMR) in controlling lead release. A ratio above 0.5 – 0.6 theoretically increases the aggressiveness of lead leaching in galvanic settings, while a lower ratio controls lead corrosion. A switch in coagulant type could significantly alter the ratio. However, a coagulant switch could also trigger changes in finished water turbidity and organics, including disinfection by-product (DBP) precursors, as well as impact sludge production. Anecdotal evidence from an Ontario water treatment utility suggested the potential applicability of a newly formulated polymer, cationic activated silica (CAS), in improving DBP precursor removal when used in concurrence with a primary coagulant. No previous scientific research had been dedicated to testing of the polymer. The present research had three primary objectives: The first was to investigate the effect of conventional coagulation with six different coagulants on the chloride-to-sulfate mass ratio as it pertains to lead corrosion in two Ontario source waters of differing quality. Additionally, the effect of coagulant choice on pH, turbidity, and organics removal was investigated. The second objective was aimed at testing potential reductions in CSMR and organics that could be brought about by the use of two polymers, cationic and anionic activated silica (CAS and AAS, respectively), as flocculant aids. Finally, the performance of a high-rate sand-ballasted clarification process was simulated at bench-scale to gauge its performance in comparison with conventional coagulation simulation techniques. The first series of jar-tests investigated the effectiveness of CAS as a primary coagulant on Lake Ontario water. In comparison with the conventional coagulants aluminum sulfate and polyaluminum chloride, CAS did not offer any apparent advantage with respect to turbidity and organics removal. Testing of CAS and AAS as flocculant aids was also conducted. Results from a full factorial experiment focused on CAS testing on Lake Ontario water showed that coagulant dose is the most significant contributor to CSMR, turbidity, DOC removal, and THM control. Generally, improvements resulting from CAS addition were of small magnitude (<15%). Reductions in CSMR were attributed to the presence of the sulfate-containing chemicals alum and sulfuric acid in the CAS formulation. Testing of sulfuric acid-activated AAS on Grand River water showed that pairing of AAS with polyaluminum chloride provides better results than with alum with respect to DOC removal (39% and 27% respectively at 60 mg/L coagulant dose). Highest turbidity removals (>90%) with both coagulants were achieved at the tested coagulant and AAS doses of 10 mg/L and 4 mg/L respectively. CSMR reductions in the presence of AAS were also attributable to sulfate contribution from sulfuric acid. Bench-scale simulation of a high-rate sand-ballasted clarification process on Grand River water showed comparable removal efficiencies for turbidity (80 – 90% at 10 mg/L), and DOC (30 – 40% at 50 mg/L). Finally, six different coagulants were tested on the two source waters for potential applicability in CSMR adjustment in the context of lead corrosion. The two chloride-containing coagulants polyaluminum chloride and aluminum chlorohydrate increased CSMR in proportion to the coagulant dose added, as would be expected. Average chloride contribution per 10 mg/L coagulant dose was 2.7 mg/L and 2.0 mg/L for polyaluminum chloride and aluminum chlorohydrate, respectively. Sulfate-contributing coagulants aluminum sulfate, ferric sulfate, pre-hydroxylated aluminum sulfate, and polyaluminum silicate sulfate reduced CSMR as coagulant dose increased, also as would be expected. The highest sulfate contributors per 10 mg/L dose were pre-hydroxylated aluminum sulfate (6.2 mg/L) and ferric sulfate (6.0 mg/L). The lowest CSMR achieved was 0.6 in Lake Ontario water at a 30 mg/L dose and 0.8 in Grand River water at a 60 mg/L dose. Highest DOC removals were achieved with the chloride-containing coagulants in both waters (35 – 50%) with aluminum chlorohydrate showing superiority in that respect. DOC removals with sulfate-containing coagulants were less, generally in the range of 22 – 41%. Specificity of critical CSMR values to source water needs to be investigated. Additionally, long term effects of sustained high or low CSMR values in distribution systems need to be further looked into. Finally, the effect of interventions to alter CSMR on other water quality parameters influencing lead corrosion such as pH and alkalinity still represent a research deficit.

Lead is a known toxin, with the ability to accumulate in the human body from as early as fetal development. Lead exposure is known to cause a myriad of health effects which are more prominent among children. Health effects upon exposure can range from renal and heart disease or potentially cancer in adults to neurotoxicity in children. The continued presence of old lead service lines and plumbing in distribution systems as well as lead-containing solders and brass fixtures in homes may contribute lead to drinking water. Recent studies have highlighted the importance of a predictor known as the chloride-to-sulfate mass ratio (CSMR) in controlling lead release. A ratio above 0.5 – 0.6 theoretically increases the aggressiveness of lead leaching in galvanic settings, while a lower ratio controls lead corrosion. A switch in coagulant type could significantly alter the ratio. However, a coagulant switch could also trigger changes in finished water turbidity and organics, including disinfection by-product (DBP) precursors, as well as impact sludge production. Anecdotal evidence from an Ontario water treatment utility suggested the potential applicability of a newly formulated polymer, cationic activated silica (CAS), in improving DBP precursor removal when used in concurrence with a primary coagulant. No previous scientific research had been dedicated to testing of the polymer. The present research had three primary objectives: The first was to investigate the effect of conventional coagulation with six different coagulants on the chloride-to-sulfate mass ratio as it pertains to lead corrosion in two Ontario source waters of differing quality. Additionally, the effect of coagulant choice on pH, turbidity, and organics removal was investigated. The second objective was aimed at testing potential reductions in CSMR and organics that could be brought about by the use of two polymers, cationic and anionic activated silica (CAS and AAS, respectively), as flocculant aids. Finally, the performance of a high-rate sand-ballasted clarification process was simulated at bench-scale to gauge its performance in comparison with conventional coagulation simulation techniques. The first series of jar-tests investigated the effectiveness of CAS as a primary coagulant on Lake Ontario water. In comparison with the conventional coagulants aluminum sulfate and polyaluminum chloride, CAS did not offer any apparent advantage with respect to turbidity and organics removal. Testing of CAS and AAS as flocculant aids was also conducted. Results from a full factorial experiment focused on CAS testing on Lake Ontario water showed that coagulant dose is the most significant contributor to CSMR, turbidity, DOC removal, and THM control. Generally, improvements resulting from CAS addition were of small magnitude (<15%). Reductions in CSMR were attributed to the presence of the sulfate-containing chemicals alum and sulfuric acid in the CAS formulation. Testing of sulfuric acid-activated AAS on Grand River water showed that pairing of AAS with polyaluminum chloride provides better results than with alum with respect to DOC removal (39% and 27% respectively at 60 mg/L coagulant dose). Highest turbidity removals (>90%) with both coagulants were achieved at the tested coagulant and AAS doses of 10 mg/L and 4 mg/L respectively. CSMR reductions in the presence of AAS were also attributable to sulfate contribution from sulfuric acid. Bench-scale simulation of a high-rate sand-ballasted clarification process on Grand River water showed comparable removal efficiencies for turbidity (80 – 90% at 10 mg/L), and DOC (30 – 40% at 50 mg/L). Finally, six different coagulants were tested on the two source waters for potential applicability in CSMR adjustment in the context of lead corrosion. The two chloride-containing coagulants polyaluminum chloride and aluminum chlorohydrate increased CSMR in proportion to the coagulant dose added, as would be expected. Average chloride contribution per 10 mg/L coagulant dose was 2.7 mg/L and 2.0 mg/L for polyaluminum chloride and aluminum chlorohydrate, respectively. Sulfate-contributing coagulants aluminum sulfate, ferric sulfate, pre-hydroxylated aluminum sulfate, and polyaluminum silicate sulfate reduced CSMR as coagulant dose increased, also as would be expected. The highest sulfate contributors per 10 mg/L dose were pre-hydroxylated aluminum sulfate (6.2 mg/L) and ferric sulfate (6.0 mg/L). The lowest CSMR achieved was 0.6 in Lake Ontario water at a 30 mg/L dose and 0.8 in Grand River water at a 60 mg/L dose. Highest DOC removals were achieved with the chloride-containing coagulants in both waters (35 – 50%) with aluminum chlorohydrate showing superiority in that respect. DOC removals with sulfate-containing coagulants were less, generally in the range of 22 – 41%. Specificity of critical CSMR values to source water needs to be investigated. Additionally, long term effects of sustained high or low CSMR values in distribution systems need to be further looked into. Finally, the effect of interventions to alter CSMR on other water quality parameters influencing lead corrosion such as pH and alkalinity still represent a research deficit.