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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Spray Aerosols From Saltwater to Freshwater Breaking Waves

Harb, Charbel 24 August 2022 (has links)
While sea spray aerosols (SSAs) generation by oceanic breaking waves continues to be an active research area, lake spray aerosols (LSAs) production by freshwater breaking waves is an emerging research field. Recent studies have linked LSAs to regional cloud processes and the aerosolization of freshwater pathogens and pollutants. Yet, differences in spray aerosol ejection between freshwater and saltwater and their impact on the water-to-air dispersal of microorganisms and pollutants are poorly understood. The goals of this dissertation work were to understand mechanistic differences between spray aerosol generation in freshwater and saltwater, develop a representation of LSA emissions in atmospheric models and evaluate their impact on regional aerosol loading, and compare the aerosolization of bacteria and microplastics by SSAs and LSAs. Experiments in a breaking-waves analogue tank revealed that the subsurface bubble plume in saltwater is characterized by more submillimeter bubbles than that in freshwater, and hence, saltwater surface foams were more persistent and were comprised of more submillimeter surface bubbles. Consequently, the average number concentration of generated SSAs was eight times higher than that of LSAs. Using these measurements, the developed LSA emission parametrization revealed that freshwater emissions were, at least, an order of magnitude lower than saltwater emissions for the same wave-breaking conditions. When implementing this emission parameterization to simulate LSA emissions from the Laurentian Great Lakes, LSAs did not contribute significantly to regional aerosol loading (< 2%), yet their impact on coarse-mode aerosols was more significant with up to a 19-fold increase in some areas. Furthermore, modeled LSAs reached up to 1000 km inland and were incorporated in the lakes' cloud layer. Despite the generation of more spray aerosols in saltier waters, cumulative salt additions in the freshwater–saltwater continuum (0-35 g/kg) led to a nonmonotonic increase in freshwater bacterial aerosolization abundance, which exhibited a peak at lower oligohaline conditions (0.5-1 g/kg). However, the aerosolization of microplastics by SSAs was one order of magnitude higher than that by LSAs. Overall, this dissertation work showed that LSA emissions are intrinsically different from SSA emissions, which influences their role in transferring microorganisms and pollutants at the air-water interface. / Doctor of Philosophy / When waves break, they entrain large volumes of air in the form of subsurface bubbles. These bubbles rise to the surface and pop ejecting small droplets into the air, also known as spray aerosols. The droplets ejected from saltwater breaking waves are referred to as sea spray aerosols (SSAs) and are extensively studied due to their important role in Earth's atmosphere. However, the ejection of lake spray aerosols (LSAs) from freshwater breaking waves is far less understood. With recent studies linking freshwater breaking waves to regional cloud processes and the transfer of aquatic pathogens to the air, a better understanding of LSAs formation and how it compares to SSAs production was needed. The goals of this dissertation work were to understand the differences between spray aerosol generation in freshwater and saltwater, develop a representation of LSA emissions in atmospheric models and assess their contribution to atmospheric aerosols, and contrast the role of LSAs and SSAs in transferring bacteria and microplastics to the air. Experiments in a spray aerosol generation tank revealed that saltwater breaking waves generate more submillimeter bubbles at the subsurface level than freshwater breaking waves and that the generated surface foam is more persistent and is comprised of smaller bubbles in saltwater. Consequently, SSA generation in the experimental tank was eight times higher than LSA generation. When implementing these results in an atmospheric model to simulate LSA emission from the surface of the Laurentian Great Lakes, it was found that the regional aerosol population was not significantly affected. However, LSA particles were transported inland up to 1000 km and reached cloud level which hints at possible implications on public health and regional climate. Despite a higher generation of aerosols by breaking waves in saltier waters, the abundance of freshwater bacteria that was dispersed to the air by spray aerosols did not increase monotonically in response to a gradual increase in freshwater salinity. Yet, microplastics transfer to the air by SSAs was an order of magnitude higher than that by LSAs. The results of this dissertation work highlight the important differences between the generation of spray aerosols by breaking waves in freshwater and saltwater and their corresponding roles in the water-to-air dispersal of microorganisms and pollutants.
22

Caracterización de microplásticos en aguas naturales y residuales, y su influencia y separación en procesos biológicos de depuración

Bretas Alvim, Clara 02 September 2022 (has links)
Tesis por compendio / [ES] Los microplásticos (MPs) son partículas de material plástico menores que 5 mm que están siendo identificadas en el agua, tierra y aire. La presencia de estos contaminantes emergentes en el medio ambiente supone una preocupación global actualmente, ya que no se sabe con exactitud su concentración y composición debido a la falta de protocolos de cuantificación e identificación estandarizados en los diferentes medios donde se encuentran. Igualmente, se desconoce el alcance de los efectos negativos que podrían provocar en el medio ambiente. La presente tesis estudia la presencia de microplásticos en diferentes corrientes de agua residual y natural, así como en fangos de depuración generados en las estaciones depuradoras de aguas residuales. El objetivo principal de la tesis consiste en evaluar diferentes protocolos para la extracción de microplásticos contenidos en muestras con diferentes características, así como su cuantificación e identificación. Para ello, se propusieron metodologías para la extracción de microplásticos en matrices con elevada carga orgánica (licor mezcla, fango digerido anaeróbicamente y fango deshidratado) y también en efluentes residuales, así como en aguas naturales tratadas (potables) y sin tratar. Asimismo, se evaluaron los posibles efectos de la presencia de microplásticos en un proceso de depuración mediante un reactor biológico de fangos activos, así como la distribución de estas micropartículas en el fango y en el efluente depurado. Además, se contempló también la posible fragmentación de microplásticos en nanoplásticos (NPs) en un sistema de depuración de aguas residuales y, por lo tanto, también se evaluaron los posibles efectos de los nanoplásticos en la biomasa de los fangos activos. Se observó que cuanto mayor era la concentración de carga orgánica en una muestra más difícil era el proceso tanto de purificación de la muestra como de identificación de microplásticos. Por lo tanto, para las muestras de fango fue necesario aplicar protocolos más complejos de extracción de microplásticos. La peroxidación, demostró ser un tratamiento eficaz de todas las muestras estudiadas, resultando en la reducción de la materia orgánica y en la mejora de la identificación visual. En los ensayos con el reactor biológico se observó una acumulación significativa de microplásticos en el licor mezcla (fango activo) frente al efluente. Esta acumulación de microplásticos en el fango puede suponer la contaminación de los suelos agrícolas cuando estos son aplicados como fertilizantes. Con el objetivo de mitigar la contaminación de suelos agrícolas por microplasticos presentes en fangos, se propuso el uso de la técnica de ultrasonidos para la extracción de estas micropartículas presentes en el licor de mezcla. Mediante esta técnica, cantidades significativas de microplasticos fueron separadas de la matriz orgánica de los fangos, que es la que se aplica al campo. Finalmente, se estudió la presencia de microfibras en aguas naturales y potables mediante a técnica de tinción con Rojo Nilo con el objetivo de investigar la viabilibilidad y limitaciones de este método. Se observó que la emisión de fluorescencia, por parte de microfibras vírgenes y microfibras separadas de estas muestras de agua, puede manifestar diferentes comportamientos de fluorescencia lo cual podría estar relacionado con el grado de degradación de los materiales de las microfibras. / [CA] Els microplàstics (MPs) són partícules de material plàstic menors que 5 mm que estan siguent identificades en l'aigua, terra i aire. Actualment, la presència d'aquests contaminants emergents en el medi ambient suposa una preocupació global, ja que no se sap amb exactitud la seua concentració i composició a causa de la falta de protocols de quantificació i identificació estandarditzats en els diferents medis on es troben. Igualment, es desconeix l'abast dels efectes negatius que podrien provocar en el medi ambient. La present tesi estudia la presència de microplàstics en diferents corrents d'aigua residual i natural, així com en fangs de depuració generats en les estacions depuradores d'aigües residuals. L'objectiu principal de la tesi consisteix a avaluar diferents protocols per a l'extracció de microplàstics continguts en mostres amb diferents característiques, així com la seua quantificació i identificació. Per a això, es van proposar metodologies per a l'extracció de microplàstics en matrius amb elevada càrrega orgànica (licor mescla, fang digerit anaeróbicamente i fang deshidratat) i també en efluents residuals, així com en aigües naturals tractades (potables) i sense tractar. Així mateix, es van avaluar els possibles efectes de la presència de microplàstics en un procés de depuració mitjançant un reactor biològic de fangs actius, així com la distribució d'aquestes micropartícules en el fang i en l'efluent depurat. A més, es va contemplar també la possible fragmentació de microplàstics en nanoplásticos (NPs) en un sistema de depuració d'aigües residuals i, per tant, també es van avaluar els possibles efectes dels nanoplásticos en la biomassa dels fangs actius. Es va observar que com més gran era la concentració de càrrega orgànica en una mostra, més difícil era el procés tant de purificació de la mostra com d'identificació de microplàstics. Per tant, per a les mostres de fang va ser necessari aplicar protocols més complexos d'extracció de microplàstics. La peroxidació, va demostrar ser un tractament eficaç de totes les mostres estudiades, resultant en la reducció de la matèria orgànica i en la millora de la identificació visual. En els assajos amb el reactor biològic es va observar una acumulació significativa de microplàstics en el licor mescla (fang actiu) enfront de l'efluent. Aquesta acumulació de microplàstics en el fang pot suposar la contaminació dels sòls agrícoles quan aquests són aplicats com a fertilitzants. Amb l'objectiu de mitigar la contaminació de sòls agrícoles per microplàstics presents en fangs, es va proposar l'ús de la tècnica d'ultrasons per a l'extracció d'aquestes micropartícules presents en el licor de mescla. Mitjançant aquesta tècnica, quantitats significatives de microplàstics van ser separades de la matriu orgànica dels fangs, que és la que s'aplica al camp. Finalment, es va estudiar la presència de microfibres en aigües naturals i potables mitjançant a tècnica de tinció amb Rojo Nil amb l'objectiu d'investigar la viabilibilitat i limitacions d'aquest mètode. Es va observar que l'emissió de fluorescència, per part de microfibres verges i microfibres separades d'aquestes mostres d'aigua, pot manifestar diferents comportaments de fluorescència la qual cosa podria estar relacionada amb el grau de degradació dels materials de les microfibres. / [EN] Microplastics (MPs) are particles of plastic material smaller than 5 mm that are being identified in water, soil, and air. The presence of these emerging contaminants in the environment is currently a global concern since their concentration and composition are unknown exactly due to the lack of standardized quantification and identification protocols in the different media where they are found. Likewise, the extent of the negative effects that they could cause in the environment is unknown. This thesis studies the presence of microplastics in different streams of wastewater and natural water, as well as in sewage sludge generated in wastewater treatment plants. The main objective of the thesis is to evaluate different protocols for the extraction of microplastics contained in samples with different characteristics, as well as their quantification and identification. For this, methodologies were proposed for the extraction of microplastics in matrices with a high organic load (mixed liquor, anaerobically digested sludge, and dehydrated sludge) and also in wastewater, as well as in treated (potable) and untreated natural waters. Likewise, the possible effects of the presence of microplastics in a depuration process using an activated sludge biological reactor were evaluated and the distribution of these microparticles in the sludge and in the final effluent. In addition, the possible fragmentation of microplastics into nanoplastics (NPs) in a wastewater treatment system was also considered and, therefore, the possible effects of nanoplastics on the biomass of activated sludge were also evaluated. It was observed that the higher the concentration of organic load in a sample, the more difficult the process of both sample purification and microplastic identification. Therefore, for the sludge samples, it was necessary to apply more complex microplastic extraction protocols. Peroxidation proved to be an effective treatment for all the samples studied, resulting in the reduction of organic matter and the improvement of visual identification. In the tests with the biological reactor, a significant accumulation of microplastics was observed in the mixed liquor (activated sludge) compared to the effluent. This accumulation of microplastics in the sludge can lead to the contamination of agricultural soils when they are applied as fertilizers. To mitigate the contamination of agricultural soils by microplastics present in sludge, the use of the ultrasound technique was proposed for the extraction of these microparticles present in the mixed liquor. Through this technique, significant amounts of microplastics were separated from the organic matrix of the sludge, which is what is applied to the field. Finally, the presence of microfibers in natural and drinking water was studied using the Nile Red staining technique to investigate the feasibility and limitations of this method. It was observed that the fluorescence emission by virgin microfibers and microfibers separated from these water samples can show different fluorescence behaviors which could be related to the degree of degradation of the microfiber materials. / Authors thank the Spanish Ministry of Science, Innovation and Universities for the financial support (Reference of the project: RTI2018-096916-B-I00) / Bretas Alvim, C. (2022). Caracterización de microplásticos en aguas naturales y residuales, y su influencia y separación en procesos biológicos de depuración [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/185696 / TESIS / Compendio
23

Microplastics in Freshwater Systems

Klein, Sascha 21 April 2016 (has links) (PDF)
Synthetic polymers are one of the most significant pollutants in the aquatic environment, because of abilities such as buoyancy and extreme persistency. Serious effects are expected from so-called microplastics (particle size <5 mm) that are reported in rivers, lakes as well as the ocean and that accumulate in sediments worldwide. In this thesis the abundance of microplastics in river shore sediments in the Rhine-Main area of Germany was studied. Therefore, a new method was developed that is based on a sodium chloride density separation with subsequent destruction of natural debris, and identification of the plastic particles by microscopy or Fourier transform infrared spectroscopy (FTIR). Using the improved density separation, microplastics were separated from river shore sediments of 12 sites originating from the river Rhine, the river Main, and the stream Schwarzbach. Large amounts of microplastic particles of up to 1 g kg-1 or up to 4000 particles kg-1 were detected in the shore sediments. The identification by FTIR showed that polyethylene, polypropylene, and polystyrene were the most abundant polymer types in the sediments, covering over 75% of all plastics identified. Transport of microplastics from tributaries to main streams was indicated by the detection of identical pellets in the River Rhine and in the Main mouth. Comparable concentrations detected by sampling one site over a period of two years suggest a constant pollution of the river shore sediments with microplastics. For deeper insights into the sorption process of organic contaminants to synthetic polymers in freshwater systems, batch experiments in synthetic freshwater were conducted to determine sorption kinetics and sorption isotherms for four selected glass state polymers (polycarbonate, poly(methyl methacrylate), polystyrene, and polyvinyl chloride) and six different model substances (carbamazepine, hexachlorocyclohexane (β/γ), 17α-ethynilestradiol, chlorpyrifos, and o,p-dichlorodiphenyltrichlorethane). Sorption to the polymer particles was observed for all contaminants increasing with the KOW values of the contaminants. Because of losses of contaminants in control samples, sorption reaction models could be applied to four out of six contaminants, and isotherms were calculated for three contaminants. Furthermore, influences of the different polymer types used were observed in the experiments. Finally, microplastics separated from sediments were extracted and analyzed by GC/MS and LC-MS/MS using target screening methods and non-target approaches. Different pesticides were identified in the polymer particles, suggesting that microplastics can act as a sink for hydrophobic contaminants. Moreover, several plastic additives such as phthalates or chlorinated flame retardants were identified. For this reason, it is very likely that microplastics act as a direct source for these chemicals in aquatic systems. The results of this thesis stress the urgency for the mitigation of the plastic particles in the aquatic environment.
24

Mikroplast i dagvatten och spillvatten : Avskiljning i dagvattendammar och anlagda våtmarker / Microplastics in Stormwater and Sewage : Removal in Stormwater Ponds and Constructed Wetlands

Jönsson, Robert January 2016 (has links)
Mikroplast, här definierat som plastobjekt mindre än 5 mm, befaras kunna göra stor skada på vattenlevande djur. Fram tills idag har studier av mikroplastreduktion främst utförts i kommunala avloppsreningsverk där mycket av plasten avskiljs. De stora spillvattenflödena gör ändå reningsverken till betydande utsläppspunkter av mikroplast till sjöar och hav. Information har hittills till stor del saknats om mikroplastförekomst i dagvatten, vilket ofta släpps ut orenat och i större volymer än spillvatten. Förekomst av mikroplast &gt;20 µm (&gt;0,02 mm) har undersökts för tre tätorters dagvatten samt för två avloppsreningsverks utloppsvatten. Avskiljning av mikroplast har undersökts för två spillvattenvåtmarker och två dagvattendammar. Båda anläggningstyper är relativt billiga och effektiva när det gäller reduktion av tungmetaller och övergödande näringsämnen. Örsundsbro våtmark och våtmark Alhagen tar båda emot behandlat spillvatten från kommunala avloppsreningsverk. I våtmark Alhagen finns även ett inlopp för dagvatten från Nynäshamn. Till dagvattenanläggningen Korsängens vattenpark leds en stor del av Enköpings dagvatten, medan Tibbledammen tar emot det dagvatten som kommer från Kungsängen i Upplands-Bro kommun. Vatten från anläggningarnas inlopp och utlopp, samt från två punkter inuti våtmark Alhagen har pumpats genom 20 µm-filter och 300 µm-filter. Provtagningen har kompletterats med insamling av mindre vattenvolymer som har filtrerats på laboratorium. Kvantifiering av mikroplast har gjorts med hjälp av stereomikroskop och vanligt förekommande objekts material har undersökts genom FTIR-spektroskopi. I våtmark Alhagens inkommande spillvatten var mikroplastkoncentrationen 4 objekt/liter, vilket liknar de koncentrationer andra svenska studier uppmätt i behandlat spillvatten. I inkommande vatten till Örsundsbro våtmark var koncentrationen över 950 objekt/liter, långt över vad andra svenska studier uppmätt i helt obehandlat spillvatten. I dagvatteninloppen var mikroplastinnehållet 5,4–10 objekt/liter, vilket indikerar på att mikroplatsutsläpp via dagvatten kan befaras vara minst lika stora som via spillvatten. I alla anläggningars inkommande vatten, förutom i våtmark Alhagens dagvatteninlopp, uppmättes höga koncentrationer av rödfärgade partiklar. Partiklarna kan vara av plast eller av annat okänt material och är till utseendet relativt lika de som andra studier påträffat i svenska kustvatten. Svarta partiklar påträffades i alla inflöden och ofta i mer än 100 gånger högre halter än de för mikroplast och röda partiklar, förutom i våtmark Alhagens spillvatteninlopp där de röda partiklarna var något fler. Partiklarna tros kunna vara däck- och vägrester eller förbränningspartiklar. Alla anläggningar visade på en tydlig avskiljning, ofta 90-100 %, för mikroplast, svarta och röda partiklar &gt;20 µm. Till följd av resultatet samt anläggningarnas variation i ålder, storlek och utformning bör dagvattendammar och anlagda våtmarker generellt kunna förväntas fungera som effektiva barriärer mot spridning av mikroplast, svarta partiklar och röda partiklar. / Microplastics (MPs), here defined as plastic objects smaller than 5 mm, are suspected to cause great harm to fish when released into lakes and oceans. Studies of MP retention have until recently mainly been done for sewage treatment plants (STPs), where much of the plastics are shown to be retained in the sludge. However, due to large water flows in STPs, they can be seen as significant points for the spreading of MPs to recipient waters. Today there isn’t much information to be found about MP contents in stormwater. Stormwater is often released untreated and depending on climate it can be released in greater volumes than sewage water from urban areas. The occurrence of MPs &gt;20 µm (&gt;0.02 mm) has been studied in two STP effluents, and in stormwater from three urban catchments. The retention of MPs has been studied for two stormwater ponds, and for two free water surface wetlands constructed for tertiary treatment of sewage. Wetland Alhagen and Örsundsbro wetland both receive the effluents of secondary STPs. In wetland Alhagen there is also a stormwater inlet from the town of Nynäshamn. To the stormwater pond Korsängens vattenpark, stormwater is lead from the town of Enköping, while the stormwater pond Tibbledammen receives stormwater from Kungsängen in Upplands-Bro municipality. Influents and effluents from the facilities, as well as water from two points within wetland Alhagen was pumped through 20 µm and 300 µm filters. In addition, water from every sampling point was collected in minor volumes for later filtration carried out in a laboratory. Quantification was done with microscopy and a number of objects were analyzed with FTIR spectroscopy for material determination. In wetland Alhagen, the sewage inlet contained 4 MPs/liter, which is similar to results for STP effluents in other Swedish studies. In Örsundsbro wetland, the incoming water contained more than 950 MPs/liter, far greater than what other studies have shown for untreated sewage. The MP concentrations in the three stormwater inlets were between 5.4-10 MPs/liter. This indicates that untreated stormwater could be seen as a pathway for MPs at least as big as treated sewage. In almost all inlets, characteristic red particles were found in great numbers and in sizes of 20-300 µm. Analysis of some of the red particles indicated that they contained plastic while others were of unknown materials. The particles had a similar appearance to red particles commonly found in Swedish coastal waters. Black particles, a kind of microscopic particles that may originate in tyre wear (i.e. MPs) or combustion, was also found in large quantities. Except for in the main influents of wetland Alhagen, where the number of red particles was slightly higher, the black particles were always found in far greater numbers than both regular MPs and red particles (often &gt;100x greater). The retention of MPs, black particles and red particles &gt;20 µm was high in all the facilities, often around 90-100 percent. Based on these results and the variation of size, design and year of construction, stormwater ponds and constructed free water surface wetlands can be seen as effective barriers against the spreading of MPs.
25

Contaminação e toxicidade de microplásticos em uma área de proteção marinha costeira / Microplastics contamination and toxicity in a coastal marine protected area

Silva, Pablo Pena Gandara e 23 August 2016 (has links)
Os plásticos têm trazido grandes benefícios aos humanos, sendo utilizados em diversas atividades como em aplicações médicas, entretenimento e na indústria de alimento. O uso crescente de plástico e seu descarte não adequado têm contribuído para o acúmulo deste detrito no meio ambiente, em especial nos oceanos onde tendem a acumular. Dentre os detritos de plástico de maior importância atualmente estão os microplásticos, que são partículas de plástico de tamanho entre 1 &#956;m e 5 mm. Os principais riscos que os microplásticos oferecem são sua grande capacidade de persistência e dispersão no ambiente marinho, sua grande afinidade por poluentes persistentes orgânicos, sua a ingestão pela biota e a transferência para a teia trófica marinha. Dentre os ambientes marinhos mais impactados por microplásticos, estão as praias arenosas, onde estas partículas tendem a acumular após encalharem ao serem trazidas pelo mar. Este estudo teve como objetivo avaliar a contaminação por microplásticos em uma praia de uma área de proteção marinha costeira e avaliar a toxicidade de pellets virgens e coletados nesta praia no desenvolvimento embriolarval de mexilhão marrom Perna perna. Foram realizadas coletas de microplásticos entre o período de fevereiro de 2014 a fevereiro de 2015 na praia de Paranapuã em duas regiões do perfil da praia (linha de maré alta e supralitoral). As partículas foram analisadas individualmente em laboratório e quanto a composição de seu polímero por Espectrofotômetro de Infravermelho por Transformada de Fourier (FT-IR). Os resultados sugerem que a poluição por microplásticos na praia de Paranapuã ocorre ao longo do ano inteiro, porém variando em concentração ao longo do tempo e com um padrão de distribuição espacial irregular na praia. A concentração de microplásticos está aparentemente relacionada com a direção do vento, tendendo a ser maior quando a direção do vento é a favor da praia. A concentração de microplásticos na praia de Paranapuã (4,72 microplásticos/m²) é próxima àquela encontrada em outras praias no mundo e da região. Os experimentos de toxicidade demonstraram que tanto pellets de plástico virgens como aqueles coletados na praia inibem o desenvolvimento embriolarval de mexilhão marrom. Entretanto, os pellets coletados na praia mostraram uma alta toxicidade que resultou numa porcentagem de larvas anormais ou mortas de 100%, significativamente superior aos pellets virgens que foi de 23,5%. Acredita-se que a diferença de toxicidade entre os pellets virgens e coletados na praia pode ser causada por contaminantes adsorvidos na superfície dos pellets coletados no campo. Os resultados deste estudo sugerem que praias de áreas de proteção marinha costeira próximas a zonas urbanas e regiões portuárias apresentam risco de contaminação por plásticos. Apesar de terem acesso restrito a humanos, os microplásticos entram nestas praias através do ambiente marinho, podendo causar efeitos adversos na fauna destes ambientes. As informações deste trabalho contribuem para a melhor compreensão dos efeitos da contaminação de ambientes costeiros por microplásticos, fornecendo informações básicas para o desenvolvimento de políticas públicas voltadas para uma gestão deste tipo de poluição em áreas de proteção ambiental. / Plastics have great benefits to humans, used in various activities such as medical applications, entertainment and food industry. The increasing use of plastic and your inappropriate disposal have contributed to the accumulation of this debris in the environment, particularly in the oceans where they tend to accumulate. Among the most important plastic waste are the microplastic which are plastic particles of size between 1 &#956;m and 5 mm. The main risks that microplastics offer are your large capacity persistence and dispersal in the marine environment, your great affinity for persistent organic pollutants and their ingestion by biota and transfer to the marine food web. Among the marine environments most impacted by microplastics are sandy beaches where these particles tend to accumulate after carried by sea. This study evaluate the contamination by microplastics on a beach of a coastal marine protected area, and assess the virgin pellets toxicity and collected on this beach in embryo-larval development of brown mussel Perna perna. Microplastics samples were collected in the period from February 2014 to February 2015 on the beach of Paranapuã in two regions of the beach (high tide line and supralittoral). The particles were analyzed individually in the laboratory and the composition of your polymer was identified for Fourier Transform infrared spectroscopy (FT-IR). The results suggest that pollution microplastics in Paranapuã beach is continuous in entire year, but varying in concentration over time and with a pattern irregular of spatial distribution on the beach. The microplastics concentration is apparently related to the wind direction, tends to be higher when the wind direction is downwind. The concentration of microplastics on the beach Paranapuã (4.72 microplastics/m²) is similar to other beaches in the world. The toxicity experiments showed that both virgin plastic pellets as those collected on the beach inhibit embryo-larval development of brown mussels. However, the pellets collected at the beach showed high toxicity resulting in abnormal or percentage of dead larvae 100%, significantly higher than for virgin pellets, which was 23.5%. It is believed that the difference in toxicity between the virgin pellets and collected on the beach can be caused by high concentration of adsorbed contaminants on the surface of the pellets collected in the field. The results of this study suggest that beaches areas of coastal marine protection near urban areas and port areas have high risk of contamination by plastics. Although this beach has access restricted to humans, microplastics enter these beaches through the marine environment, potentially causing adverse effects on the local fauna of these environments due to your high toxicity. The information from this study contribute to a better understanding of the effects of contamination of coastal environments by microplastics, providing basic information for the development of public policies for management of this type of pollution in the areas of environmental protection.
26

Efeitos de microplástico na fisiologia do mexilhão Perna perna (Bivalvia: Mytilidae) / Microplastics effects on the physiology of the Mussel Perna perna (Bivalvia:Mytilidae)

Ascer, Liv Goldstein 18 November 2015 (has links)
Dentre as diferentes poluições presentes nos oceanos, o plástico é provavelmente, aquele que leva aos maiores impactos ambientais, sendo encontrado de praias e manguezais à giros no meio dos oceanos. Os macroplásticos, cujo tamanho é superior a 5mm, são maiores em volume e provocam um impacto socioambiental importante, porém os microplásticos, fragmentos menores que 5mm, estão em maior quantidade e podem provocar danos em organismos marinhos filtradores como mexilhões e ostras. Apesar da sua grande presença nos oceanos, ainda não se estabeleceu com clareza se causam efeitos somente físicos, por um aumento de material particulado não orgânico ingerido, ou se seus efeitos podem ser de origem química, devido à quantidade de contaminantes que possuem. Para estudar o impacto que essas partículas têm em organismos filtradores, o mexilhão Perna perna, espécie bioindicadora abundante na costa brasileira, foi exposto a partículas de polietileno encontradas em cosméticos nacionais. O microplástico foi adquirido diretamente da indústria e precisou ser identificado. A análise de FT&minus;IR mostrou que o plástico era polietileno de baixa densidade. Os organismos então foram expostos ao polietileno, virgem ou lixiviado, em duas concentrações (0,5 g&frasl;L e 2,5 g&frasl;L) por diferentes períodos (12,24,48,96 e 144 horas). Após os experimentos, os mexilhões foram coletados e dissecados e a resposta de seis biomarcadores foi analisada: O Tempo de Retenção do Vermelho Neutro nos hemócitos, Danos ao DNA e Lipoperoxidação nas brânquias e os níveis de três proteínas de estresse (AIF&minus;1, pP38&minus;MAPK e HSP&minus;70) nas glândulas digestivas. Todos os biomarcadores foram afetados pela exposição ao polietileno, porém um padrão no resultado não pôde ser observado. Os fatores de exposição analisados (Concentração, Período e Tratamento do Plástico) individualmente, ou combinados, levaram a respostas diferentes e até mesmo opostas em alguns casos. A coleta de indivíduos de P. perna in situ na região do Porto de Santos mostrou que todos os bancos naturais possuem organismos contaminados. Os resultados deste trabalho mostram que a fisiologia do mexilhão P. perna é modificada após a exposição aguda ao polietileno. Um maior número de biomarcadores deve ser analisado futuramente para elucidar quais vias estão efetivamente sendo ativadas ou inibidas. O alto nível de contaminação dos mexilhões da região do porto de Santos é um fator alarmante que deve ser discutido pela sociedade com o intuito de se criar soluções para o problema da poluição por plástico nos oceanos antes que este afete a saúde humana. / Among all different pollutants, plastic debris is one of the main environmental impacts, being found from beaches and mangrove to gyres in the middle of the oceans. Macroplastics, with size above 5mm, are larger in volume and are an important social and environmental problem, but microplastics, fragments less than 5mm can be most harmful for filter feeding animals such as mussels and oysters. However, it is still debatable if its effects are physical, due to the increase in indigestible material; or chemical, due to plastic additives such as phthalates or PCBs. To study the impact that these particles can have in those animals, the brown mussel Perna perna (Bivalvia) an abundant and an organism easy to maintain in the laboratory, was exposed to virgin or leached polyethylene (PE) microbeads, used as abrasives in Brazilian cosmetics. Polyethylene was acquired directly from the industry and therefore needed to be identified. Analysis of FT&minus;IR showed that the plastic was Low Density Polyethylene. The microplastic exposure had two concentrations (0.5 and 2.5g&frasl;l) and different periods of time (12, 24, 48, 96 and 144 hours). After the experiment, the organisms were dissected and the levels of six biomarkers were analyzed: Neutral Red Retention Time by the Hemocytes, Lipid Peroxidation and DNA Damages in the Gills and the response levels of three stress proteins (pP38&minus;MAPK, AIF&minus;1 and HSP&minus;70) in the Digestive Glands. All biomarkers were affected by the PE exposure, but the results did not follow a pattern. The exposure factors analyzed (Concentration, Period of Time and Plastic Treatment), alone or combined, led to different and sometimes opposite responses. In Situ collected samples in the Santos Harbour area showed that all natural mussel\'s beds analyzed had microplastics contaminated mussels. The results of this work showed that microplastics acute exposure in P. perna modifies its physiology. More biomarkers should be used to clarify which pathways are being activated or inhibited. The high levels of contamination of important commercial mussel\'s beds in the Santos Harbour area, is an alarming sign for the community, that should start working together to solve the plastic pollution problem in our oceans before starts to affect human health.
27

Analysis, occurence, release and degradation of phthalate esters (PAEs) in Mediterranean coastal sea / Analyse, distribution, production et dégradation d’esters de phtalates (PAEs) en zone côtière méditerranéenne

Paluselli, Andrea 15 February 2018 (has links)
Les phtalates (PAEs) sont un groupe de contaminants organiques émergents qui sont devenus une préoccupation majeure en raison de leur omniprésence dans le milieu marin et de leurs effets perturbateurs sur le système endocrinien. Cependant, leur répartition en Méditerranée est assez mal connue, principalement en raison des difficultés analytiques et du risque élevé de contamination des échantillons lors du processus analytique. En outre, les débris de plastique en milieu marin contiennent des additifs comme les PAEs, qui sont ajoutés lors de l’étape de fabrication du plastique. Dans la première partie de cette thèse, une méthode analytique a été optimisée et validée pour la détermination de 8 PAEs à l'état de traces en milieu marin. Brièvement, 1L d'échantillon filtré est passé à travers des cartouches de verre contenant 200 mg d'Oasis HLB, puis élué à l’aide de 6mL d'acétate d'éthyle. Notre méthode donne des rendements d’extraction compris entre 95 et 115 % et des blancs acceptables. Dans un second temps, un suivi annuel de la contamination de la Baie de Marseille a été effectué de décembre 2013 à novembre 2014. Les résultats ont montré la présence de 7 PAEs, avec des concentrations totales variant de 130 à 1330 ng L-1. Dans la dernière partie de cette thèse, deux échantillons de plastique communs (sac de poubelle et gaine de câble électrique) ont été incubés dans de l'eau de mer naturelle dans des conditions contrôlées de laboratoire, de manière à évaluer la migration de PAEs depuis ces matériaux en fonction de différentes conditions environnementales comme la température, la présence de lumière, ou encore la présence de bactéries. / Phthalic Acid Esters (PAEs) are a group of emerging organic contaminants that have become a serious issue because of their ubiquitous presence on the marine environment worldwide and for the endocrine disrupting effects in animals and humans. However, little is known about their distribution in the Ocean, mainly because of analytical difficulties and the high possibility of ambient sample contamination. Plastic debris in marine environment includes resin pellets, macro- and microplastic fragments, and contains additives such as PAEs that might be released in the aquatic environment in unknown proportion. In our work, we improved an analytical method for the determination of 8 PAEs, at trace levels in marine and fresh waters. In the first part of the thesis, the method was validated for different seawater salinities and wastewater treatment plant outlet. By passing 1 L of sample through glass cartridges packed with 200 mg of Oasis HLB and eluted with 6 mL of ethyl acetate, the recoveries of 8 PAEs ranged from 95 to 115 % with acceptable blank values (below 0.4-4.0 % of the masses measured in different seawater samples). In a second part, PAE distribution in the Marseille Bay has been evaluated though a one-year monitoring from December 2013 to November 2014. The results showed the occurrence of six PAEs with total concentrations ranging from 130 to 1330 ng L-1. In the last part of this thesis, two common plastic samples as trash plastic bags and insulation layer of electric cables were incubated in natural seawater in laboratory conditions and studied for the release of PAE. Release ws observed for the different PAEs with kinetics varying according to the plastic type.
28

Contaminação e toxicidade de microplásticos em uma área de proteção marinha costeira / Microplastics contamination and toxicity in a coastal marine protected area

Pablo Pena Gandara e Silva 23 August 2016 (has links)
Os plásticos têm trazido grandes benefícios aos humanos, sendo utilizados em diversas atividades como em aplicações médicas, entretenimento e na indústria de alimento. O uso crescente de plástico e seu descarte não adequado têm contribuído para o acúmulo deste detrito no meio ambiente, em especial nos oceanos onde tendem a acumular. Dentre os detritos de plástico de maior importância atualmente estão os microplásticos, que são partículas de plástico de tamanho entre 1 &#956;m e 5 mm. Os principais riscos que os microplásticos oferecem são sua grande capacidade de persistência e dispersão no ambiente marinho, sua grande afinidade por poluentes persistentes orgânicos, sua a ingestão pela biota e a transferência para a teia trófica marinha. Dentre os ambientes marinhos mais impactados por microplásticos, estão as praias arenosas, onde estas partículas tendem a acumular após encalharem ao serem trazidas pelo mar. Este estudo teve como objetivo avaliar a contaminação por microplásticos em uma praia de uma área de proteção marinha costeira e avaliar a toxicidade de pellets virgens e coletados nesta praia no desenvolvimento embriolarval de mexilhão marrom Perna perna. Foram realizadas coletas de microplásticos entre o período de fevereiro de 2014 a fevereiro de 2015 na praia de Paranapuã em duas regiões do perfil da praia (linha de maré alta e supralitoral). As partículas foram analisadas individualmente em laboratório e quanto a composição de seu polímero por Espectrofotômetro de Infravermelho por Transformada de Fourier (FT-IR). Os resultados sugerem que a poluição por microplásticos na praia de Paranapuã ocorre ao longo do ano inteiro, porém variando em concentração ao longo do tempo e com um padrão de distribuição espacial irregular na praia. A concentração de microplásticos está aparentemente relacionada com a direção do vento, tendendo a ser maior quando a direção do vento é a favor da praia. A concentração de microplásticos na praia de Paranapuã (4,72 microplásticos/m²) é próxima àquela encontrada em outras praias no mundo e da região. Os experimentos de toxicidade demonstraram que tanto pellets de plástico virgens como aqueles coletados na praia inibem o desenvolvimento embriolarval de mexilhão marrom. Entretanto, os pellets coletados na praia mostraram uma alta toxicidade que resultou numa porcentagem de larvas anormais ou mortas de 100%, significativamente superior aos pellets virgens que foi de 23,5%. Acredita-se que a diferença de toxicidade entre os pellets virgens e coletados na praia pode ser causada por contaminantes adsorvidos na superfície dos pellets coletados no campo. Os resultados deste estudo sugerem que praias de áreas de proteção marinha costeira próximas a zonas urbanas e regiões portuárias apresentam risco de contaminação por plásticos. Apesar de terem acesso restrito a humanos, os microplásticos entram nestas praias através do ambiente marinho, podendo causar efeitos adversos na fauna destes ambientes. As informações deste trabalho contribuem para a melhor compreensão dos efeitos da contaminação de ambientes costeiros por microplásticos, fornecendo informações básicas para o desenvolvimento de políticas públicas voltadas para uma gestão deste tipo de poluição em áreas de proteção ambiental. / Plastics have great benefits to humans, used in various activities such as medical applications, entertainment and food industry. The increasing use of plastic and your inappropriate disposal have contributed to the accumulation of this debris in the environment, particularly in the oceans where they tend to accumulate. Among the most important plastic waste are the microplastic which are plastic particles of size between 1 &#956;m and 5 mm. The main risks that microplastics offer are your large capacity persistence and dispersal in the marine environment, your great affinity for persistent organic pollutants and their ingestion by biota and transfer to the marine food web. Among the marine environments most impacted by microplastics are sandy beaches where these particles tend to accumulate after carried by sea. This study evaluate the contamination by microplastics on a beach of a coastal marine protected area, and assess the virgin pellets toxicity and collected on this beach in embryo-larval development of brown mussel Perna perna. Microplastics samples were collected in the period from February 2014 to February 2015 on the beach of Paranapuã in two regions of the beach (high tide line and supralittoral). The particles were analyzed individually in the laboratory and the composition of your polymer was identified for Fourier Transform infrared spectroscopy (FT-IR). The results suggest that pollution microplastics in Paranapuã beach is continuous in entire year, but varying in concentration over time and with a pattern irregular of spatial distribution on the beach. The microplastics concentration is apparently related to the wind direction, tends to be higher when the wind direction is downwind. The concentration of microplastics on the beach Paranapuã (4.72 microplastics/m²) is similar to other beaches in the world. The toxicity experiments showed that both virgin plastic pellets as those collected on the beach inhibit embryo-larval development of brown mussels. However, the pellets collected at the beach showed high toxicity resulting in abnormal or percentage of dead larvae 100%, significantly higher than for virgin pellets, which was 23.5%. It is believed that the difference in toxicity between the virgin pellets and collected on the beach can be caused by high concentration of adsorbed contaminants on the surface of the pellets collected in the field. The results of this study suggest that beaches areas of coastal marine protection near urban areas and port areas have high risk of contamination by plastics. Although this beach has access restricted to humans, microplastics enter these beaches through the marine environment, potentially causing adverse effects on the local fauna of these environments due to your high toxicity. The information from this study contribute to a better understanding of the effects of contamination of coastal environments by microplastics, providing basic information for the development of public policies for management of this type of pollution in the areas of environmental protection.
29

Microplásticos têxteis : emissão de fibras sintéticas na lavagem doméstica / Textile microplastics: synthetic fibers\' emission during domestic washings

Cesa, Flavia Salvador 23 August 2017 (has links)
Há tempos a ubiquidade dos materiais plásticos no meio ambiente é assunto de discussão, com destaque para as partículas menores, ditas microplásticos (< 5 milímetros). Fibras provenientes de materiais têxteis são um subgrupo dos microplásticos e têm origem em diversas fontes, incluindo lavagens domesticas, uma vez que filtros de lavadoras e sistemas de tratamento de esgoto não são desenhados especificamente para retê-las. Quando no meio ambiente, estes materiais podem alcançar concentrações até milhares de unidades por metro cúbico, ficando disponíveis a uma gama de espécies. Neste cenário, o presente estudo teve como objetivo avaliar parâmetros de lavagem, e características têxteis que pudessem influenciar no desprendimento de fibras em efluentes de lavadoras domesticas. Foram realizados experimentos com dez sucessivas lavagens individuais, com e sem detergente, para quatro tipos de artigo: algodão (como padrão de comparação), acrílico, poliéster e poliamida. Os efluentes foram então filtrados (< 1 milímetro, 500 mícrons, 63 mícrons, 8 mícrons) e pesados. Resultados demonstram que todos os artigos têxteis liberaram fibras na lavagem. Dez sucessivas lavagens representaram queda na massa desprendida, bem como o uso de detergentes em comparação a lavagens sem detergente. Diferenças entre artigos sugeriram variação conforme características têxteis, onde algodão liberou mais fibras, seguido de acrílico, poliamida e poliéster. Em relação ao tamanho das fibras, a maioria ficou retida no filtro da lavadora (< 1 milímetro) e na peneira de 63 mícrons, mostrando o potencial de diminuição de porosidade do filtro. A visualização de fibras em papel-filtro de 8 mícrons sugere a existência de fibras micro e nano. Convertendo massa para numero de unidades, a lavagem individual de um artigo têxtil mostrou desprender entre milhares e centenas de milhares de fibras. Para uma extrapolação mundial, cerca de 40,4 mil toneladas de algodão e 21,5 mil toneladas de fibras sintéticas seriam liberadas em efluentes de esgoto. No Brasil estes valores corresponderiam, respectivamente, a 1,6 mil e 860 toneladas ano. Caso fossem tratadas em estações de tratamento de esgoto em condições ideais, seriam liberadas, em um ano, cerca de 737 toneladas de fibras sintéticas em escala mundial e 29 toneladas em escala nacional. Uma vez em cursos d\'água, estas fibras atingiriam, em ultima instância, o ambiente marinho, indicando a necessidade por soluções que combatam este tipo de poluição, sem antes deixar de explorar as lacunas do conhecimento, relacionadas, no âmbito têxtil, especialmente às diferenças metodológicas entre os estudos. / Since decades, the ubiquity of plastic materials in the environment has been a matter of discussion. Smaller pieces, named microplastic (< 5 millimeters) gained more attention recently and are now the focus of several studies. Textile fibers are a subgroup of microplastics and can be originated from several sources, including domestic washings, once filters and sewage treatment plants are not specifically designed to retain them. In the environment, these materials can reach concentrations up to millions of units per cubic meter, being available to many species. The objective of the present study was to evaluate washing parameters and also textile characteristics, which could influence in fibers emission from domestic washing machines. Experiments were done in ten successive times, with and without detergent, for four types of articles: cotton (as a pattern for comparison), acrylic, polyester and polyamide. Resulting effluents were then filtered in different porosities (< 1 millimeter, 500 microns, 63 microns, 8 microns), weighted, related to mass of textile articles and simulated regarding number of fibers. Results demonstrated that all textile articles emitted fibers during domestic washings. Ten successive washings represented a decrease in the emitted mass, as well as the use of detergent in relation to washings without the product. Differences between articles suggested variation of results according to textile characteristics, where the ranking of emission was: cotton, acrylic, polyamide and polyester. When considering the size of fibers, the majority was retained in the filter of the washing machine (porosity < 1 millimiter) and in 63 microns sieve, when compared to 500 microns sieve, showing the importance of the filter of the washing machine and the potential to decrease its porosity. Fibers retained in the filter- paper of 8 microns, couldnt be weighted because of its low mass, but their visualization suggests the existence of fibers in micro and nano scales. Converting mass to number of fibers, one individual washing was responsible for something between thousands and hundred of thousands of units. When extrapolating values to a global perspective, it reaches something around 40.4 thousand tonnes of cotton per year and 21.5 thousand tonnes of synthetic fibers per year. In a Brazilian perspective, these values correspond, respectively, to 1.6 thousand tonnes year and 860 tonnes year. If this effluents were all treated in sewage treatment plants, in ideal conditions, still they would release something like 737 tonnes of synthetic fibers per year in a global scale and 29 tonnes of synthetic fibers per year in a national scale. Once in water bodies, those fibers would reach the marine environment, indicating the necessity of solutions that could impair this kind of pollution, not before solving knowledge gaps, specially related, in the textile area, to methodology differences between studies
30

Analyzing microplastics in soils : Evaluating canola oil extractions

Bottone, Anna January 2019 (has links)
Small fragments of artificial polymers (microplastics, MPs) has been reported for multiple environmental matrices from our planet. The omnipresent existence of these microplastics even in remote polar areas have raised concern about their potential environmental impacts and created a need for effective and standardized analytical methods targeting their detection in environmental samples. So far, no methods have been developed for detecting microplastics in organic-rich soils. In this master thesis, I evaluate two analytical methods (both based on canola oil extractions) targeting microplastics in two contrasting soil matrices; one mineral rich (sandy mineral soil from a Podzol) and the other by organic matter (sample from a Histosol). I hypothesize that the detection of microplastic has a bias that depends on specific plastic particle properties (size, polymer type and morphology) as well as on the organic content of soil samples. My results show that the recovery of added plastics is strongly dependent on particle size and diminishes with decreasing microplastics length. This result was repeated by both extraction approaches.  Polymer shape and soil characteristics (organic matter content) affect MPs recovery if oil extractions are conducted without pre-treatment (oxidation) step. Here, fibers proved most difficult to detect and low recoveries suggested that the method was not applicable to organic rich samples. The addition of a pretreatment step including oxidation with sodium hypochlorite improved recoveries for organic rich samples and removed the effect of soil type and polymer shape. Hence, the use of a pretreatment is essential to extract MPs from organic-rich soils, but it also decreases the overall recovery for all type of studied polymers and mostly fibers. My study suggests that there is a substantial bias when detecting MPs in soils that is causing a general underestimation, especially for small, fibrous particles in organic rich soils.

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