Dentre os vários poluentes que ameaçam o ambiente marinho estão os pellets de plástico, matéria prima em forma de grânulos de 5mm que estão sendo liberados nas etapas de produção, utilização e transporte. Este projeto visa o entendimento da contaminação das praias da Enseada de Santos, litoral do Estado de São Paulo, como uma área piloto para se compreender os padrões de distribuição e identificar a composição química e taxa de entrada. Os pellets foram encontrados a até 2m de profundidade, mas se concentraram na porção mais superior do sedimento (com cerca de 1.100 pellets por 0,1m3 nos 30cm superiores) e na região do pós-praia (136 pellets/0.018m3 na porção mais elevada). A distribuição ao longo da praia mostrou que os pellets se concentraram nas áreas mais próximas ao Canal de Santos, com uma taxa média de 82 pellets/0.036m3, e chegando à densidade máxima de 139/0.036m3, fato relacionado principalmente com a circulação da Baía e correntes provenientes do Canal. A taxa de entrada não mostrou um padrão ao longo da baía e períodos do ano, mas o maior número de pellets foi encontrado no Inverno (377/m²), após um evento de tempestade. Quase 80% eram Polietileno e cerca de 20% Polipropileno; o tamanho médio foi cerca de 2.5 a 3.0mm de altura e 3.5 a 4.0mm de diâmetro; e quase 70% tinha coloração clara à amarelada. A maior parte dos pellets analisados apresentou-se relativamente preservada. As prováveis fontes de emissão (porto e indústrias) estão localizadas na região estuarina. / Among the various pollutants that threaten the ocean are plastic pellets, prime resource in the form of 5mm granules that are being dumped in the environment during production, utilization and transport stages. This project aims to understand of the contamination of the beaches of the Santos Bay, coast of the state of São Paulo, as a pilot area to address the patterns of distribution and identify the chemical composition and rate of entry of pellets. The pellets were found even at 2m depths, but were concentrated at the upper level of sediment (with approximately 1100 pellets per 0.1m³ on the top) and in the back-shore region (136 pellets/0.018m³ at the higher level). The distribution along the beach showed that the pellets were concentrated in the areas closer to the Santos estuarine Channel, with an average rate of 82 pellets/0.036m³, and reaching a maximum density of 139/0.036m³, a fact directly related to the circulation of the bay and channel currents. The rate of entry did not show a pattern along the bay and periods of the year, but the greatest number of pellets were found during the winter after a storm (377/m²). Almost 80% were polipropilene and about 20% poliethylene. The average size was circa 2.5 to 3.0mm in length and 3.5 to 4.0mm in diameter and almost 70% were clear colored or yellowish. The greatest part of the analyzed pellets appeared relatively preserved. The probable sources of emission (harbor and industries) are located in the estuarine region.

The widespread environmental occurrence of chemical pollutants presents an ongoing threat to human and ecosystem health. This challenge is compounded by the diversity of chemicals used in industry, commerce, agriculture and medicine, which results in a spectrum of potential fates and exposure profiles upon their inevitable release into the environment. This, in turn, confounds risk assessment, where challenges persist in accurate determination of concentrations levels, as well as spatial and temporal distributions, of pollutants in environmental media (e.g., water, air, soil and sediments). Passive sampling technologies continue to gain acceptance as a means for simplifying environmental occurrence studies and, ultimately, improving the quality of chemical risk assessment. Passive samplers rely on the accumulation of a target analyte into a matrix via molecular diffusion, which is driven by the difference in chemical potential between the analyte in the environment and the sampling media (e.g., sorbent phase). After deployment, the target analyte can be extracted from the sampling media and quantified, providing an integrated, time-weighted average pollutant concentration via a cost-effective platform that requires little energy or manpower when compared to active (e.g., grab) sampling approaches. While a promising, maturing technology, however, limitations exist in current commercially available passive samplers; they are typically limited in the types of chemicals that can be targeted effectively, can require long deployment times to accumulate sufficient chemical for analysis, and struggle with charged analytes. In this dissertation, we have designed a next-generation, nanofiber sorbent as a passive sampling device for routine monitoring of both legacy and emerging organic pollutant classes in water and sediment. The polymer nanofiber networks fabricated herein exhibit a high surface area to volume ratio (SA/V values) which shortens the deployment time. Uptake studies of these polymer nanofiber samplers suggest that field deployment could be shortened to less than one day for surface water analysis, effectively operating as an equilibrium passives sampling device, and twenty days for pore water analysis in soil and sediment studies. By comparison, most commercially available passive sampler models generally require at least a month of deployment before comparable analyses may be made. Another highlight of the nanofiber materials produced herein is their broad target application range. We demonstrate that both hydrophobic (e.g., persistent organic pollutants, or POPs, like PCBs and dioxin) and hydrophilic (e.g., emerging pollutant classes including pesticides, pharmaceuticals and personal care products) targets can be rapidly accumulated with our optimal nanofibers formulations. This suggests that one of our devices could potentially replace multiple commercial passive sampling devices, which often exhibit a more limited range of analyte targets. We also present several approaches for tailoring nanofiber physical and chemical properties to specifically target particular high priority pollutant classes (e.g., PFAS). Three promising modification approaches validated herein include: (i) fabricating carbon nanotube-polymer composites to capture polar compounds; (ii) introducing surface-segregating cationic surfactants to target anionic pollutants (e.g., the pesticide 2,4-D and perfluorooctanoic acid or PFOA); and (iii) use of leachable surfactants as porogens to increase nanofiber pore volume and surface area to increase material capacity. Collectively, outcomes of this work will guide the future development of next generation passive samplers by establishing broadly generalizable structure-activity relationships. All told, we present data related to the influence on the rate and extent of pollutant uptake in polymer nanofiber matrices as a function of both physical (specific surface area, pore volume, and diameter) and chemical (e.g., bulk and surface composition, nanofiber wettability, surface charge) nanofiber properties. We also present modeling results describing sampler operation that can be used to assess and predict passive sampler performance prior to field deployment. The electrospun nanofiber mats (ENMs) developed as passive sampling devices herein provide greater functionality and allow for customizable products for application to a wide range of chemical diverse organic pollutants. Combined with advances in and expansion of the nanotechnology sector, we envision this product could be made commercially available so as to expand the use and improve the performance of passive sampling technologies in environmental monitoring studies.

Foi explorado o desenvolvimento de fotocatalisadores híbridos ZnO/Xerogel de carbono, visando aumentar a eficiência quântica do processo de degradação de poluentes orgânicos persistentes. Especificamente, foi estudada a preparação do híbrido ZnO-xerogel de carbono, sendo esta, a maior inovação tecnológica deste projeto, considerando que o efeito catalítico deste híbrido não foi estudado na literatura. O uso do xerogel de carbono na preparação do semicondutor-material carbonoso é justificado pela excelente condutividade elétrica, elevada área superficial e porosidade, além de sua estrutura porosa ser facilmente manipulada por modificações nos parâmetros de síntese. A escolha do tanino como precursor do xerogel visa à diminuição de custos e impactos ambientais, além de acrescentar valor à inovação tecnológica proposta. A influência do pH e rota de síntese foram avaliados, assim como a influência da temperatura de calcinação nas propriedades dos materiais. A espectroscopia por refletância difusa foi a técnica empregada para determinação da energia de gap das amostras. A morfologia, a análise elementar, a estrutura cristalina dos materiais, a estrutura química e a constituição dos materiais foram determinadas por microscopia eletrônica de varredura, espectrometria de energia dispersiva, difratometria de raios X, infravermelho e espectroscopia Raman, respectivamente. O balanço de cargas na superfície do material foi analisado pela metodologia do ponto de carga zero (PZC). A ação fotocatalítica do material foi avaliada através da decomposição de 4-clorofenol e bisfenol A, determinada através da espectroscopia no UV-Visível. Todos os materiais apresentam a estrutura cristalina hexagonal do óxido de zinco (wurtzita). Os materiais sem tanino em sua composição também apresentam a fase de hidroxicloreto de zinco mono-hidratado. Os difratogramas de raios-X e valores de bandgap obtidos confirmam a incorporação do carbono na estrutura cristalina do óxido de zinco. Os materiais produzidos via rota alcoólica apresentam menores valores de tamanho de cristalito e partícula, assim como um maior teor de grafite em sua composição e maior área superficial, enquanto que os materiais produzidos em solução aquosa apresentam menores valores de energia de gap. Todos os materiais apresentaram atividade fotocatalítica quando submetidos à radiação solar e visível, sendo que os materiais com proporções intermediárias entre xerogel de carbono e óxido de zinco se mostraram superiores para o processo de fotodegradação. Os materiais produzidos via alcoólica são superiores aos produzidos em solução aquosa, no que tange o processo de fotocatálise. Os valores máximos encontrados para a degradação de 4-clorofenol e bisfenol A foram de 88% e 78%, respectivamente, obtidos pelo material XZnC 3.0 (EtOH). A temperatura de calcinação e quantidade de hidróxido de potássio utilizados na síntese influenciam significativamente as propriedades dos materiais, de modo que as condições ótimas para a síntese dos materiais foram de calcinação em 300oC e 8 g de hidróxido de potássio utilizadas na síntese. O mecanismo de fotocatálise é fortemente influenciado pela geração de radicais hidroxilas e os materiais apresentam estabilidade para reciclo em processos industriais. / The development of ZnO/Carbon xerogel hybrid photocatalysts was studied, in order to increase the quantum efficiency of the degradation process of persistent organic pollutants. Specifically, the preparation of the ZnO-carbon xerogel hybrid was studied, being this the most significant technological innovation of this project, considering that the catalytic effect of this hybrid was not studied in the literature. The use of carbon xerogel in the preparation of the semiconductor-carbonaceous material is justified by its excellent electrical conductivity, high surface area and porosity, the latter being easily manipulated by modifications in the synthesis parameters. The choice of tannin as the precursor of the xerogel aims at reducing costs and environmental impacts, adding value to the proposed technological innovation. The influence of the pH and route of synthesis were evaluated, as well as the influence of the calcination temperature on the properties of the materials. Diffuse reflectance spectroscopy was the technique used to determine the gap energy of the samples. The morphology, elemental analysis, crystalline and chemical structure of the materials were determined by scanning electron microscopy, dispersive energy spectrometry, X-ray diffractometry, infrared and Raman spectroscopy, respectively. The charge balance on the material surface was analyzed by the point of zero charge methodology (PZC). The photocatalytic action of the material was evaluated by the decomposition of 4-chlorophenol and bisphenol A, determined by UV-Visible spectroscopy. All materials have the hexagonal crystalline structure of zinc oxide (wurtzite). The materials without tannin in their composition also present the zinc hydroxychloride monohydrate phase. The X-ray diffractograms and bandgap values obtained confirm the incorporation of the carbon in the crystalline structure of the zinc oxide. The materials produced via the alcohol route have lower values of crystallite and particle size, as well as a higher content of graphite in their composition and larger surface area, while the materials produced in aqueous solution have lower values of gap energy. All the materials presented photocatalytic activity when subjected to visible and solar radiation, and the materials with intermediate proportions between carbon xerogel and zinc oxide were superior for the photodegradation process. The materials produced via alcohol route are superior to those produced in aqueous solution, as far as the photocatalysis process is concerned. The maximum values found for the degradation of 4-chlorophenol and bisphenol A were 88% and 78%, respectively, obtained by the material XZnC 3.0 (EtOH). The calcination temperature and amount of potassium hydroxide used in the synthesis significantly influence the properties of the materials, so that the optimum conditions for the synthesis of the materials were calcination at 300 °C and 8 g of potassium hydroxide used in the synthesis. The mechanism of photocatalysis is strongly influenced by the generation of hydroxyl radicals and the materials present stability for recycling in industrial processes.

Abstract not available

Market gardening is commonly characterised by intensive cultivation, high inputs of both organic and inorganic fertilisers, chemical over/misuse, frequent irrigation, and a low degree of soil cover. While market gardening is readily perceived to be detrimental to waterways, there is remarkably little data to quantify the impacts. Soil and nutrient loss in stormwater runoff varies with soil type, climate and production systems. Therefore local data are needed to determine the impact of market gardening on the Hawkesbury-Nepean. This should lead to a better understanding of how land management influences runoff quantity and quality so that practices can be improved. Objectives of this research were to : quantify sediment, N and P loss and assess the implications for waterways; relate sediment, N and P losses to specific land management practices and assess their impacts on profitability; and, reflect on this research in terms of extension and adoption of better land management. An 8.8 ha property with 6.6 ha of market garden was used as a case study in the Hawkesbury-Nepean Catchment. Soil samples were collected at the beginning and end of the study. Sediment core samples were collected from the drainage channel. A rainfall simulator was used to compare runoff volume from green manure and bare fallow beds. The research produced several recommendations for the extension and adoption of improved land management. In order to reduce sediment, N and P losses in stormwater, the primary focus should be on improving soil and nutrient management, in particular matching fertiliser inputs more closely to nutrient requirements. The secondary focus should be on utilising structural measures, in particular farm dams, to prevent pollutants from entering waterways. The outcome should be decreased costs to the farmer and decreased impacts on waterways. The use of N-fixing green manure to decrease the use of poultry manure should be explored. / Master of Science (Hons)

Pervious pavements in car parks and driveways reduce peak discharge and the volume of runoff flowing in to urban drains and improve the water quality by trapping the sediments in the infiltrated water. This reduces the risk of pollutants such as suspended solids and particle bound chemicals such as phosphorous, nitrogen, heavy metals and oils and hydrocarbons entering receiving waters. The key objectives of the study are to establish relationships between rainfall and pervious pavement runoff and quantify improvements to infiltrated stormwater quality through the pervious pavement. The field experimental results were used to calibrate the PCSWMMPP model and to develop water flow and quality improvement transfer functions of the MUSIC model for concrete block and turf cell pavements. The research reported herein has demonstrated that pervious pavements can be introduced as a sustainable stormwater management initiative and as a key Water Sensitive Urban Design feature to deliver numerous benefits to the environment. The outcomes from the study will be useful in designing environmentally friendly car parks, pedestrian paths, light traffic drive ways, sporting grounds and public areas in the future. Land developers and local government authorities will be major beneficiaries of the study which has increased the understanding of the use of pervious pavements and explored a number of issues that previously inhibited the wider use of pervious pavements in practice.

<p>The aim was to study the prevalence of asthma, eczema, allergy and respiratory symptoms among pupils in Shanxi province, China, in relation to home and school environment and outdoor air pollution. In one study there was a low prevalence of self-reported asthma, eczema and pollen or pet allergy among pupils (9-20y). Rural childhood and consumption of fruit and fish were negatively associated with asthma or allergy, while current urban residency and consumption of hamburgers tended to be risk factors. In another study in junior high school pupils, similar low prevalence of asthma and allergy was found. Compared with pupils at the same age in Uppsala, Sweden, asthma and allergy were less common while daytime attacks of breathlessness were more common in Chinese pupils. Parental asthma or allergy was a predictor of asthma symptoms. Factors in the home environment such as new floor, new furniture and ETS exposure were risk factors for asthma symptoms. Crowdedness, dust amount, CO₂, temperature and air humidity were negatively associated with respiratory symptoms. Microbial chemical components like muramic acid and ergosterol, markers for bacteria and fungi, were negatively associated with wheeze or daytime attacks of breathlessness. The associations with endotoxin varied depending on the length of 3-hydroxy fatty acids of the lippopolysaccharides (LPS). Among outdoor air pollutants, SO₂ and formaldehyde were positively associated with asthma symptoms or respiratory infections. In addition, indoor SO₂, NO₂ and formaldehyde were positively associated with asthma symptoms and respiratory infections. In conclusion, rural childhood and dietary factors can be protective for asthma and allergy. ETS and chemical emissions from new material at home can be risk factors for asthmatic symptoms. In the school environment, factors of indoor origin seemed to be generally protective for respirator symptoms while factors of outdoor origin seemed to be risk factors.</p>

Thesis (M.Eng.)--Memorial University of Newfoundland, 2005. / Bibliography: leaves 130-137.

The aim was to study the prevalence of asthma, eczema, allergy and respiratory symptoms among pupils in Shanxi province, China, in relation to home and school environment and outdoor air pollution. In one study there was a low prevalence of self-reported asthma, eczema and pollen or pet allergy among pupils (9-20y). Rural childhood and consumption of fruit and fish were negatively associated with asthma or allergy, while current urban residency and consumption of hamburgers tended to be risk factors. In another study in junior high school pupils, similar low prevalence of asthma and allergy was found. Compared with pupils at the same age in Uppsala, Sweden, asthma and allergy were less common while daytime attacks of breathlessness were more common in Chinese pupils. Parental asthma or allergy was a predictor of asthma symptoms. Factors in the home environment such as new floor, new furniture and ETS exposure were risk factors for asthma symptoms. Crowdedness, dust amount, CO2, temperature and air humidity were negatively associated with respiratory symptoms. Microbial chemical components like muramic acid and ergosterol, markers for bacteria and fungi, were negatively associated with wheeze or daytime attacks of breathlessness. The associations with endotoxin varied depending on the length of 3-hydroxy fatty acids of the lippopolysaccharides (LPS). Among outdoor air pollutants, SO2 and formaldehyde were positively associated with asthma symptoms or respiratory infections. In addition, indoor SO2, NO2 and formaldehyde were positively associated with asthma symptoms and respiratory infections. In conclusion, rural childhood and dietary factors can be protective for asthma and allergy. ETS and chemical emissions from new material at home can be risk factors for asthmatic symptoms. In the school environment, factors of indoor origin seemed to be generally protective for respirator symptoms while factors of outdoor origin seemed to be risk factors.

This study aims to investigate the influence of air pollutant concentration and meteorological factors on the atmospheric visibility in Taipei basin. First of all, we collected air quality data measured by ambient air quality monitoring stations of EPA (Environmental Protection Administration) and the meteorological factors monitored by Tamsui and Taipei meteorological stations separately, based on the range of three observation directions. We then analyzed the data by PCA (principal component analysis) to determine the main effective factors on atmospheric visibility under low visibility condition. In order to comprehend the spatial and temporal distribution of atmospheric visibility, we collected the atmospheric visibility data from Taipei meteorological observation stations for the past twenty-two years (1984~2005), it showed that the atmospheric visibility increased gradually. The seasonal variation of visibility was also observed, the best season was autumn (10.7 km) and the worst season was spring (7.5 km). Furthermore, according to the monthly statistical results, the visibility trends in the Taipei Basin can be separated into three typical periods: low visibility period (January to May), transitional period (June to September), high visibility period (October to December). The average atmospheric visibilities observed at the Tamsui, Songshan, and Sindian directions were 10.66 km , 9.54 km and 8.44 km, respectively. In general, the visibility at the Tamsui direction was slightly higher than those from other two directions. The results showed that atmospheric visibility was influenced not only by air pollutant levels and meteorological factors, but also affected by local topography of Taipei Basin. This study revealed that the atmospheric visibility data led on the Tamsui, Songshan observation directions is better. Four intensive observations of atmospheric visibility were conducted during March 28~April 1, July 4~8, September 19~23, and November 14~18 in the year of 2006, respectively. The results showed that the atmospheric visibilities at Tamsui direction were generally higher than other two directions. The visibilities observed in the afternoon were generally higher than those in the morning. Results obtained from the principle component analysis showed that the atmospheric visibility in the Taipei Basin were mainly influenced by PM10, NOx and CO, that mobile sources was the main cause of low visibility in the Taipei Basin. In addition, Tamsui region were affected by PM10 and SO2 more than Songshan and Sindian regions, which was influenced by neighboring industrial and the power plants. In the meteorological factors, wind speed and temperature have more influence on atmospheric visibility, however, the relationship between atmospheric visibility and relative humidity was somehow irregular. The analysis of the spatial distribution of air pollutants showed that low visibilities can not be caused only by high air pollutant concentration within the region, it may caused by the rise of air pollutant concentration in the transition region.