Dissertations / Theses on the topic 'Macroalgae biomass'

Seaweed biomass has been identified as a potential fermentation substrate for third generation biofuel processes due to its high carbohydrate content and its potential for mass cultivation without competing for agricultural land, fresh water and fertilisers. This thesis aimed to develop and advance existing processes to convert brown seaweeds into bioethanol. The main kelp species chosen as biomass candidates were Laminaria digitata, Laminaria hyperborea, Saccharina latissima and Alaria esculenta due to their abundance in Scottish waters and their identified potential for mariculturing. These kelp species were chemically characterised to identify seasonal variations, to recommend suitable seaweed candidates for bioethanol production and predict best harvest times. This has only been demonstrated before on one species - L. digitata. The chemical composition analyses were carried out over a 14 months sampling period, which focused on the storage carbohydrates laminarin and mannitol and the structural carbohydrates alginate, cellulose, fucoidan and xylose. In addition to carbohydrates the protein, nitrogen, carbon, polyphenol, ash and metal content was also profiled. Chemical profiling identified all four kelps as potential fermentation candidates, where maximum carbohydrate contents coincided with lowest ash and polyphenol content, usually seen in autumn. Biomass pre-treatment and saccharification are up-stream processes aimed at enhancing extraction of carbohydrates and converting those into fermentable substrates. Conversion of seaweed biomass into fermentation substrate evaluated acids and enzymes for seaweed pre-treatment and saccharification. Methodologies focused on optimising saccharification yields were developed to identify process critical parameters and develop methods for routine analysis of seaweed biomass. Results demonstrated that dilute acid hydrolysis was were less effective in releasing fermentable sugars, and also resulted in higher salinities compared to enzymatic hydrolysis using hemicellulosic and cellulosic enzymes, which were the preferred method of saccharification. All seaweeds in this thesis were assessed as fermentation substrates using the yeasts S. cerevisiae and P. angophorae, that principally ferment glucose or mannitol, respectively. Small-scale fermentation assays were developed for both yeasts to maximise ethanol yields and achieve process robustness. Both yeasts achieved a maximum ethanol yield of 0.17 g g-1 using Laminaria spp. On the basis of results, S. cerevisiae is recommended as the most useful yeast at this present point for ethanol fermentation from seaweed hydrolysates because of its tolerance to high salinity and ethanol concentrations. As salinity can negatively affect non-halotolerant enzymes, isolation of marine microorganisms was therefore carried out with the aim to highlight their enzymatic potential in seaweed saccharification. This was achieved through the isolation of two members of the genus Pseudoalteromonas, where saccharification yields using crude intracellular enzyme preparations exceeded those of dilute acids. In addition, the fermentative potential of microbial isolates as future ethanologenic strains was also evaluated. Understanding of the metabolic pathways is needed to fully assess the potential of those strains for genetic alteration. In conclusion, this thesis has demonstrated that up to ca. 20 g l-1 of ethanol can be produced from kelp species that grow on the west coast of Scotland. The procedure developed and used to produce ethanol requires further development, specifically the need for ethanol-fermenting microorganisms that can utilize mannitol and alginate; use of marine-adapted enzymes for saccharifiction; and the development of processes to achieve substrate concentration with reduced salinities. Comparison of theoretical ethanol yields from seaweed biomass with ethanol yields from terrestrial crops showed that the complete utilisation of all three major seaweed carbohydrates (laminarin, mannitol and alginate) from kelp species is needed for the process to be able to compete with 1st generation biofuel processes.

This thesis presents a techno-economic investigation of the generation of electricity from marine macroalgae (seaweed) in the UK (Part 1), and the production of anhydrous ammonia from synthesis gas (syngas) generated from biomass gasification (Part 2). In Part 1, the study covers the costs from macroalgae production to the generation of electricity via a CHP system. Seven scenarios, which varied the scale and production technique, were investigated to determine the most suitable scale of operation for the UK. Anaerobic digestion was established as the most suitable technology for macroalgae conversion to CHP, based on a number of criteria. All performance and cost data have been taken from published literature. None of the scenarios assessed would be economically viable under present conditions, although the use of large-scale electricity generation has more potential than small-scale localised production. Part 2 covers the costs from the delivery of the wood chip feedstock to the production of ammonia. Four cases, which varied the gasification process used and the scale of production, were investigated to determine the most suitable scale of operation for the UK. Two gasification processes were considered, these were O2-enriched air entrained flow gasification and Fast Internal Circulating Fluidised Bed. All performance and cost data have been taken from published literature, unless otherwise stated. Large-scale (1,200 tpd) ammonia production using O2-enriched air entrained flow gasification was determined as the most suitable system, producing the lowest ammonia-selling price, which was competitive to fossil fuels. Large-scale (1,200 tpd) combined natural gas/biomass syngas ammonia production also generated ammonia at a price competitive to fossil fuels.

This thesis focused on the extraction of value-added biomaterials from brown seaweed and the potential applications of the extracted biomaterials as well as an analysis of the prospects of building a general bio-refinery pathway for brown seaweed. Microwave assisted extraction (MAE) was used as an innovative extraction method for phlorotannins extraction from brown seaweed. Comparison of the extraction efficiency of phlorotannins by means of MAE and conventional solid–liquid extraction from three species of brown seaweeds determined that an optimized MAE protocol increased yields by 70%. The antioxidant activities of phlorotannins and their thermal stabilities were determined. Phlorotannins extracted from C. flexuosum by MAE had the highest antioxidant activity. The composition of the most active phlorotannin extracts was also determined by HPLC-MS. Phlorotannins extracted from C. flexuosum were polymerised to make polymerised phlorotannin nanoparticles which were tested for their ability to remove heavy metal ions from aqueous solution. Calcium carbonate (CaCO3) and hybrid CaCO3–phlorotannin microparticles were also prepared for comparation. Polymerised phlorotannin particles showed highly efficient removal capacity of Pb2+ from aqueous solution (460mg/g of adsorbent). Compared with CaCO3 microparticles, the Pb2+ removal capacity of hybrid CaCO3–phlorotannin microparticles was increased when the initial Pb2+ concentration was below 1000 mg/L. However, at higher initial Pb2+ concentrations, the synergistic adsorption effect diminished. A cascading bio-refinery process was also developed for brown seaweed. This process sequentially extracted of several product streams including pigments, mannitol, phlorotannins, carbohydrates, alginate and residual seaweed. The proposed biorefinery process may provide the possibility of fully utilizing brown seaweed to provide both bio-materials and bio-energy.

Lake Illawarra is a shallow barrier lagoon, located on the south-eastern coast of Australia. Eutrophication, referring to the enrichment of water by inorganic plant nutrients (primarily nitrogen and phosphorus), is one of the key environmental problems in Lake Illawarra. Management of macroalgae in Lake Illawarra is a major issue; excessive blooms of macroalgae, resulting in odours, access problems and community concern over Lake health, have led to many management strategies, including direct harvesting of algal biomass. Little information is available on the factors responsible for excessive growth of macroalgae in Lake Illawarra, although over supply of nutrients has often been cited as the primary cause. The aim of this study was to investigate the distribution, diversity, biomass and nutrient relationships of seagrasses and macroalgae in Lake Illawarra, and to determine what contribution, if any, macrophytes make to the Lake’s nutrient budget. Firstly, detailed species lists and taxonomic descriptions were prepared for macrophytes occurring in Lake Illawarra, between June 2000 and July 2003. This study focused primarily on shallow (< 1 m depth), inshore areas of Lake Illawarra, where problematic macroalgal blooms frequently occur. Seagrasses found in Lake Illawarra are Zostera capricorni, Ruppia megacarpa, Halophila ovalis and Halophila decipiens. In addition, 35 species of macroalgae were recorded and described; these included: 14 species from 7 genera of green macroalgae; 9 species from 9 different genera of brown macroalgae; and, 8 species from 8 genera of red macroalgae. The biomass of seagrasses and macroalgae in Lake Illawarra were documented seasonally (winter and summer) at four key Lake Illawarra sites; these included two R. megacarpa sites and two Z. capricorni sites. Average R. megacarpa and Z. capricorni dry weight (DW) biomasses (above and below-ground material) ranged from 54.8 - 440 g DW m 2 and 58.1 - 230 g DW m 2, respectively. Significant die-back, particularly of Z. capricorni, occurred in winter; summer biomasses were up to 1.5 - 3.9 times higher than winter biomasses. Below-ground material (roots and rhizomes) comprised 20 - 45 % and 40 - 67 % of total plant biomass for R. megacarpa and Z. capricorni, respectively. Macroalgal biomass in 2000-03 was notably lower than in previous decades; this may be due to drought, as well as improvements in water quality. Maximum biomasses of macroalgae recorded in the present study were 150 - 370 g DW m 2. Algal blooms were composed primarily of the filamentous chlorophytes, Chaetomorpha linum and Chaetomorpha billardierii. The highest seagrass (R. megacarpa) and macroalgal biomasses usually occurred at the Oasis Caravan Park site, located along the eastern Lake Illawarra peninsula. Tissue nutrient analyses were conducted on the most abundant seagrasses (Z. capricorni and R. megacarpa) and macroalgae occurring at four sites in Lake Illawarra, between spring 2000 and winter 2002. Total C contents of macrophytes varied from 23.3 - 42.0 % C for seagrasses, and 28.0 - 39.7 % C for macroalgae. The δ13C and δ15N contents of seagrasses ranged from -7.7 to 15.9 ‰ and 0.7 - 9.0 ‰, respectively. The most significant seasonal variations in seagrass δ13C contents and, to a lesser extentδ15N contents, occurred in Z. capricorni located at the source of fresh water input, Mullet Creek. Macroalgae showed a greater variation in isotopic signatures than the seagrasses, ranging from 4.9 to 19.8 ‰ (δ13C) and 1.8 - 14.6 ‰ (δ15N). Differences between species at the same site were often more significant than differences between the same species at different sites. Seagrass leaf N and P contents ranged from 1.74 - 4.13 % (mean ± s.e.: 2.62 ± 0.05 % N) and 0.12 - 0.59 % P (mean ± s.e.: 0.31 ± 0.01 % P); leaf N and P contents were typically double those of roots/rhizomes. N contents varied between species and sites, but P contents of Z. capricorni were usually significantly higher than R. megacarpa. Z. capricorni C and N contents increased in winter, corresponding to lower winter biomasses. Seagrass leaf biomass and tissue P contents peaked in summer 2002, which may be related to higher water column P concentrations in summer. Tissue N and P contents of macroalgae were more variable than those of the seagrasses, and ranged from 0.85 - 3.95 % N and 0.03 - 0.58 % P. The average C/P (808 ± 65) and N/P (47.9 ± 3.47) molar ratios of macroalgae were typically double those of the seagrasses. Low concentrations of tissue P, with respect to N, in R. megacarpa and macroalgae implied P limitation on several occasions, particularly when macrophyte biomasses were low. High tissue N contents in Lake Illawarra macrophytes suggested N limitation of biomass formation rarely occurred. Evidence of P, rather than N, limitation in macrophytes is surprising considering most data suggests N limitation of phytoplankton production in Lake Illawarra. The estimated pools of N and P contained in Lake Illawarra macrophyte biomass were similar to those present in the water column, but appeared minute when compared to the N and P stored within Lake Illawarra sediment. Laboratory culture experiments were conducted to evaluate the response of the most problematic alga, Chaetomorpha linum, to nutrient enrichment. Water temperatures of 20 - 25°C were found to promote the highest growth rates (up to 27 % WW d 1) of C. linum, but high growth rates (13 % WW d 1) were also recorded at 10°C, the lowest winter water temperature recorded in Lake Illawarra. Enrichment with N, rather than P, had the greatest effect on C. linum; growth rates were significantly reduced in treatments without added N, but treatments with N-alone were statistically similar to N+P treatments. It was concluded that in Lake Illawarra, C. linum was strongly nitrogen limited. The ability of C. linum to grow successfully in culture, under a range of nutrient treatments, and without added phosphorus, in particular, correlates with the excessive growth of this alga in Lake Illawarra. This study has made a significant contribution to the understanding of seagrass and macroalgal growth, biomass and distribution in Lake Illawarra. This information will assist with the long-term management of macroalgal problems in Lake Illawarra.

We examined effects of the macroalgae Laurencia and Palisada spp. on epifauna within seagrass beds of Thalassia testudinum. First we conducted a field survey of Thalassia testudinum beds with varying densities of Laurencia and Palisada spp. Second, we conducted a field experiment, manipulating natural and simulated Laurencia and Palisada spp. In the field survey, we found that total faunal biomass (g m-2) increased significantly with Laurencia and Palisada spp. cover. In the experiment, natural Laurencia and Palisada spp. supported an increased density (No. m-2) of fauna, however, faunal values were highest in the simulated algae treatment. This suggests that the mechanism of increased density/biomass due to Laurencia and Palisada spp. is structural complexity. Since habitat quality in Thalassia testudinum beds may be mediated by associated macroalgae, these small-scale habitat factors need to be incorporated in habitat and ecosystem conservation plans.

Green macroalgae represent an attractive source of renewable carbon. Conversion of algal biomass to useful products requires depolymerization of the cell wall polysaccharides cellulose and ulvan. Cellulose saccharification has been widely studied and involves synergistic action of endoglucanases, exoglucanases, and β-glucosidases. The enzymatic depolymerization of ulvan has not received the same attention and additional studies are required in order to fully understand the mechanisms involved in its biodegradation. Synthetic biology offers the possibility of importing modules such as biomass-degrading systems and biofuel producing pathways from different organisms into a genetically tractable host such as Escherichia coli. In this study it was shown that E. coli expressing the glycosidase CHU2268 of Cytophaga hutchinsonii grows well on cello-oligosaccharides such as cellohexaose, and co-expression with the endoglucanase CenA of Cellulomonas fimi allows growth on untreated crystalline cellulose. Moreover, a model for ulvan utilization was built for the first time based on a polysaccharide utilization locus from the alga-associated flavobacterium Formosa agariphila. It was also shown that F. agariphila, is able to grow using biomass from the green macroalga Ulva lactuca as its sole carbon source, and enzymes with ulvanase activity are induced by the presence of this alga in the culture medium. Enzymes for ulvan depolymerization from F. agariphila, including an ulvan lyase, xylanases and rhamnosidases, were cloned using the PaperClip DNA assembly method and expressed in active form in E. coli. Furthermore, a secretion system based on the use of the Antigen 43 was successfully used to secrete an active ulvan lyase using E. coli and ribosome binding sites of different strengths were studied and used to optimize the system. These results represent a first step for the design of a microorganism capable of utilizing green macroalgal biomass for the production of biofuels and other valuable bio-products.

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CAPES
Os impactos ambientais causados pelo homem têm sido fonte de grande preocupação, tendo em vista as conseqüências negativas que afetam o equilíbrio ecológico do meio. A área apresenta uma variedade ambientes e agrega vários habitats, o que a torna um dos principais pontos de diversidade de algas no Estado Pernambucano. A partir dai surgiu à necessidade de realizar um estudo na região, com o objetivo de fazer um inventario das algas presentes em Suape, e assim, contribuir para o conhecimento sobre a comunidade ficológica da região, gerando subsídios para fins de preservação e futuros trabalhos de monitoramento. As coletas foram divididas em 2 etapas distintas, a primeira realizada no período de janeiro de 1998 a julho de 1999, apenas inventariando a flora, a segunda etapa, foi realizada trimestralmente, de Janeiro de 2009 a julho de 2010, inventariando minuciosamente a flora algológica da região e quantificando a biomassa das macroalgas dos recifes da região portuária de Suape. Nesta etapa foram coletadas 378 amostras para fins de biomassa e diversidade, sendo estas distribuídas em três transects, aleatoriamente. Foram coletados parâmetros abióticos concomitantemente (NO2, NO3, PO4, turbidez e Sólidos Totais Suspensos) Foram registradas Baia da região portuária de Suape um total de 136 taxa de macroalgas, o que a caracteriza como a área de maior riqueza desse grupo o litoral do estado de Pernambuco. É importante ressaltar o registro de um novo táxon para o litoral brasileiro Acetabularia farlowii e novas adições para a flora ficológica do litoral do estado de Pernambuco (Acetabularia myriospora, Ceratodictyon planicaule, Ceramium vagans e Laurencia oliveirana). A biomassa das algas encontradas na região variou de 181,3±20,7 no mês de Janeiro de 2009 a 62,5±6,0 no mês de Julho de 2010. Foi possível observar variações significativas entre o mês de janeiro de 2009 e Julho de 2009 (z=3.549; p<0,05), Janeiro de 2010 (z=3.523; p<0,05) e Julho de 2010 (z=3.6904; p<0,05), entre os meses de Abril 2010 e Julho de 2009 (z=3.1889; p<0,05), Janeiro de 210 (z=3.1632; p<0,05) e Julho de 2010 (z=3.3304; p<0,05). As diferenças encontradas foram, principalmente, observadas pela influência das dragagens e pela sazonalidade, tendo em vista que os únicos meses que apresentaram grandes biomassa foram os meses de Janeiro de 2009 (quando ainda não haviam dragado) e o mês de abril de 2010 (quando as dragagens estavam sendo finalizadas). O mês de julho de 2010 apresentou valores de biomassa baixos, provavelmente pela sazonalidade e pelo aumento de chuvas no período. Das espécies que constituem a comunidade de macroalgas na região, as Palisada perforata, Centrosceras clavulatum, Gelidiella acerosa e Acanthophora spicifera, foram as que apresentaram maiores freqüências, com 86, 47, 41 e 40% respectivamente. Com base nos dados obtidos, é possível afirmar que as comunidades de algas aparentam estar bem conservadas na região do Complexo portuário de Suape, tendo em vista o elevado número de taxa e a alta freqüência de espécies normalmente encontradas em outros recifes de arenito no litoral do estado.

No presente trabalho, pretendeu-se avaliar a alga marinha Sargassum filipendula na sua capacidade de remoção do metal cobre na presença do metal cálcio, de modo a verificar o efeito da presença do cálcio, proveniente do hidróxido de cálcio (cal hidratada), utilizado no tratamento primário de efluentes por precipitação química. Para tanto, foi realizado primeiramente o estudo da cinética de biossorção de cobre e cálcio em regime de batelada, nas concentrações de 50 e 200 g/mL, e em seguida foi estudado o equilíbrio da biossorção de cobre e cálcio, também em regime de batelada, utilizando soluções isoladas e combinadas de cobre e cálcio, em concentrações variadas, com biomassa lavada com água corrente e com HCl 0,1 mol/L, de modo a verificar se houve melhora na biossorção com a protonação da biomassa. Os resultados do estudo cinético da biossorção do cobre e do cálcio mostraram, em todos os casos, que o equilíbrio ocorreu até os 30 minutos iniciais e que os resultados do cobre se ajustaram melhor a um modelo cinético de segunda ordem, enquanto que os resultados do cálcio não se ajustaram a nenhum dos dois modelos propostos. Foi possível verificar ainda uma relação direta entre biossorção de cobre e liberação de elementos alcalinos e alcalino-terrosos, sugerindo o envolvimento de troca-iônica durante o processo. Já com os resultados de estudo do equilíbrio da biossorção dos metais cobre e cálcio, foi possível obter algumas conclusões, dentre as quais podemos destacar a predileção pelo modelo de isotermas de Langmuir e a interferência na biosorção do cobre causada pela presença do cálcio na solução. Nesta etapa, foi possível ainda estabelecer novamente a correlação de permuta entre os metais cobre e alcalinos/alcalino terrosos. Os modelos de pseudo-primeira ordem e segunda ordem foram utilizados para avaliar a cinética de adsorção dos íons metálicos pela biomassa, enquanto que os modelos das isotermas de Langmuir e de Freundlich, foram utilizados para a representação do equilíbrio da biossorção
In the present work it was intended to evaluate the seaweed Sargassum filipendula in its ability to remove the copper metal in the presence of calcium metal in order to verify the effect of the presence of calcium from the calcium hydroxide (hydrated lime) used in primary treatment of effluents by chemical precipitation. Therefore, it was first carried out to study the kinetics of sorption of copper and calcium under batch, at concentrations of 50 and 200 g/mL, and then was studied equilibrium sorption of copper and calcium, also under batch, using solutions isolated and combined calcium and copper in varied concentrations, with biomass washed with water and with 0.1 M HCl in order to check if an improvement in biosorption with the protonation of biomass. Results from the kinect study of copper and calcium showed in all cases that the balancing occur until the first 30 minutes and the results of copper were best fitted to a second order kinetic model, while the results of the calcium not adjusted to either of the two proposed models. It was also possible to see a direct relationship between biosorption of copper and release of alkaline elements, alkaline - earth metals, suggesting the involvement of ion exchange during the process. Already with the results of the results of the study of equilibrium biosorption of copper and calcium, it was possible to obtain some conclusions, among which we can highlight the predilection for the Langmuir isotherm model and interference in biosorption of copper caused by the presence of calcium in the solution. At this stage, it was still possible to re establish the correlation between the exchange of copper and alkali / alkaline earth. The models of pseudo- first order and second order were used to evaluate the kinetics of adsorption of metal ions by biomass, while the models of Langmuir isotherm and Freundlich, will be used to represent the equilibrium of biosorption

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Química, Florianópolis, 2014.
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A indústria petroquímica representa atualmente um setor preponderante na economia brasileira. A gestão sustentável dos recursos hídricos é uma preocupação crescente da indústria petroquímica, fazendo com que o desenvolvimento de tecnologias amigas do ambiente para tratamento de efluentes petroquímicos seja um mercado em crescimento. O objetivo deste trabalho consiste na valorização da macroalga marinha Pelvetia canaliculata (Linnaeus) através de seu uso como trocador de cátions para remoção e recuperação de íons de cádmio, chumbo, cobre e zinco em soluções aquosas, como um processo alternativo de remoção de metais pesados presente em efluentes petroquímicos. O mecanismo de biossorção dos cátions divalentes de chumbo, cádmio, cobre e zinco, usando a alga bruta, revelou-se um processo de troca iônica com os cátions presentes na superfície da alga, Na+, K+, Ca2+ e Mg2+, com uma estequiometria de 1:1 entre íons com a mesma carga (Ca2+ e Mg2+ com Pb2+,Cd2+, Cu2+ e Zn2+) e 2:1 entre íons de cargas diferentes (K+ e Na+ com Pb2+, Cd2+, Cu2+ e Zn2+). Inicialmente, procedeu-se a um tratamento da alga de forma a converter todos os grupos funcionais na forma Na+. A partir dos resultados da digestão da alga na forma Na+ foi possível obter a quantidade de íons sódio ligados aos grupos funcionais (2,5 mmol/g), o que sugere a presença de 2,5 mmol de grupos funcionais ácidos por grama de alga. Através das técnicas de FTIR e de titulação potenciométrica foi possível determinar que os principais grupos funcionais presentes na superfície da alga responsáveis pela ligação dos metais são os grupos funcionais ácidos (fracamente ácido (grupos carboxílicos) e fortemente ácidos (grupos sulfônicos)), representando no total 2,5 mmol/g. Foram realizadas experiências cinéticas em sistema fechado, a partir das quais se determinou o tempo de equilíbrio e o valor da difusividade homogênea do íon metálico no biossorvente. O equilíbrio de biossorção dos íons chumbo e cádmio em solução aquosa, usando a alga na forma Na+ foi estudado a diferentes valores de pH, verificando-se um aumento significativo da capacidade de biossorção com o aumento do pH. A capacidade máxima de biossorção dos íons chumbo a pH 4,0 foi de 1,25 mmol/g (259 mg/g) e a de cádmio a pH 4,5 foi 1,25 mmol/g (140 mg/g), permitindo concluir que todos os grupos funcionais presentes na superfície da alga foram ocupados. O equilíbrio de biossorção usando a mistura Pb2+/Cd2+/Cu2+/Zn2+ revelou que existe competitividade entre os íons metálicos para os sítios ativos presentes na superfície da biomassa, diminuindo a capacidade de biossorção de cada íon metálico, face ao sistema usando apenas um íon metálico. No entanto, a capacidade total de biossorção da mistura Pb2+/Cd2+/Cu2+/Zn2+ é similar à obtida no sistema usando apenas um íon metálico. A esterificação da alga, bloqueando os grupos carboxílicos e os grupos sulfônicos, levou a uma redução de mais de 80% da capacidade de biossorção, indicando que estes grupos funcionais são os principais responsáveis pela remoção dos íons metálicos. Um modelo de equilíbrio de troca iônica, considerando os grupos funcionais carboxílicos e sulfônicos na forma Na+, foi capaz de prever os dados de equilíbrio nos diferentes sistemas estudados (Pb2+/Na+/H+, Cd2+/Na+/H+ e Pb2+/Cd2+/Cu2+/Zn2+/Na+/H+) em sistema fechado permitindo calcular as constantes de seletividade entre os íons. Um modelo de transferência de massa considerando uma resistência à difusão intrapartícula, foi capaz de descrever as cinéticas de biossorção a diferentes valores de pH iniciais da solução, nos diferentes sistemas estudados. Estudou-se também o processo de biossorção dos íons metálicos em sistema contínuo usando uma coluna de leito fixo, à escala laboratorial e piloto. As curvas de ruptura foram obtidas para os diferentes sistemas estudados (Pb2+/Na+/H+, Cd2+/Na+/H+, Cu2+/Na+/H+, Zn2+/Na+/H+ e Pb2+/Cd2+/Cu2+/Zn2+/Na+/H+). A dessorção dos íons metálicos foi estudada no sistema contínuo usando como eluente uma solução de HNO3 (0,1 M).

Abstract : The petrochemical industry currently represents a major sector in the Brazilian economy. The sustainable management of water resources is a growing concern in the petrochemical industry, and consequently the development of environmentally friendly technologies for the treatment of petrochemical effluent is a growing market. The objective of this work is the valorisation of marine brown macroalgae Pelvetia canaliculata through its use as cation exchanger for removal and recovery of cadmium, lead, copper and zinc ions from aqueous solution, as an alternative process for heavy metals removal from petrochemical effluents. The mechanism of lead, cadmium, copper and zinc divalent cations biosorption using the raw algae, has been attributed to an ion exchange process between light metal present in the surface of algae, Na+, K+, Ca2+ and Mg2+, and ions in aqueous solution, Pb2+, Cd2+, Cu2+ and Zn2+, with a stoichiometry ratio of 1:1 between ions of the same charge (Ca2+, Mg2+ with Pb2+, Cd2+, Cu2+ e Zn2+) and 2:1 between ions of different charge (K+ and Na+ with Pb2+, Cd2+, Cu2+ e Zn2+). Initially, the raw alga was treated with a NaCl solution in order to convert all functional groups in the Na+ form. From Na loaded algae digestion results it was possible to obtain the amount of sodium ions bound to the functional groups (2.5 mmol/g), suggesting the presence of 2.5 mmol of acid functional groups per gram of algae. Through FTIR and potentiometric titration techniques it was determined that the main functional groups present on the surface of the algae responsible for metal binding are acidic functional groups (weakly acidic (carboxylic groups) and strongly acidic (sulfonic groups)), representing a total of 2.5 mmol/g. Batch kinetic biosorption experiments were carried out to determine the equilibrium time and the homogeneous diffusion coefficient of each metal in the biosorbent. Batch equilibrium biosorption of lead and cadmium ions in aqueous solution using the Na loaded algae was studied at different pH values. A significant increase in the equilibrium biosorption capacity with increase of pH was observed. Maximum biosorption capacity of lead ions at pH 4.0 was 1.25 mmol/g (259 mg/g) and for cadmium ions at pH 4.5 was 1.25 mmol/g (140 mg/g), which means that all functional groups present on the surface of the algae were occupied. Batch equilibrium biosorption for the Pb2+/Cd2+/Cu2+/Zn2+ system showed the competition between metals ions for the active binding sites presents in the surface of the biomass, decreasing the biosorption capacity of each metal ion when comparing with the single metal ion system. However, the total biosorption capacity for the Pb2+/Cd2+/Cu2+/Zn2+ mixture was similar to that obtained for the single metal ion system. Algae esterification, blocking carboxylic and sulfonic groups, led to a reduction of more than 80% of biosorption capacity, indicating that these functional groups are primarily responsible for metal ions removal. A mass transfer model, considering a resistance to the intraparticle diffusion, was able to describe the biosorption kinetics at different initial solution pHs, in single and quaternary metal systems. An ion exchange equilibrium model, considering carboxylic and sulfonic functional groups in the Na+ form, was able to predict the equilibrium data in all the systems studied (Pb2+/Na+/H+, Cd2+/Na+/H+ and Pb2+/Cd2+/Cu2+/Zn2+/Na+/H+), being able to calculate the selectivity coefficients among ions. The biosorption of the metal ions was also studied in a continuous system using a packed bed configuration, at lab and pilot scale. Biosorption breakthrough curves were also obtained for all the systems studied (Pb2+/Na+/H+, Cd2+/Na+/H+, Cu2+/Na+/H+, Zn2+/Na+/H+ e Pb2+/Cd2+/Cu2+/Zn2+/Na+/H+). Desorption of metal ions, in the continuous system, was also evaluated using HNO3 solution (0.1 M) as eluent.

Orientador: Ciro Cezar Zanini Branco
Banca: Rogério Antonio Krupek
Banca: Cleto Kaveski Peres
Resumo: Estudos anteriores sugerem que, aparentemente, existem padrões específicos para descrever a composição e a estrutura das comunidades de macroalgas em ambientes lóticos em função das características do bioma ao qual estão inseridos. Neste contexto, a presente dissertação objetivou avaliar, de forma comparativa, a composição, a estrutura das comunidades e a distribuição espacial das comunidades de macroalgas lóticas de duas unidades de conservação (UCs) com biomas distintos: Campos no Parque Estadual de Vila Velha (PVV) e Floresta Estacional Semidecidual no Parque Nacional do Iguaçu (PNI). Em adição, pretendeu-se comparar as comunidades de macroalgas nas quatro estações do ano, a fim de se verificar a possível existência de padrões temporais. As amostragens foram realizadas em 5 segmentos de riacho de 10 m de extensão, em cada UC, através da técnica da transeção, onde as variáveis abióticas (temperatura, oxigênio, pH, condutividade, turbidez, profundidade e velocidade da correnteza) foram mensuradas, assim como a presença e a abundância de cada espécie de macroalga. Estes parâmetros bióticos foram avaliados através da análise visual do leito do rio/riacho. As amostragens foram feitas uma vez a cada estação do ano. O estudo taxonômico registrou 37 macroalgas no total, sendo 16 táxons de ocorrência exclusiva no PVV, 18 táxons de ocorrência exclusiva no PNI e apenas 3 táxons com ocorrência em ambos os parques (Phormidium retzii, Hildenbrandia angolensis e Batrachospermum puiggarianum). O táxon com maior ocorrência no PVV foi o Zygogonium sp. (9 ocorrências), e no PNI o estágio "Chantransia" pygmaea foi o que ocorreu em maior número de pontos amostrados (15). Em relação aos tipos morfológicos, foram encontrados: filamentos livres (24%), filamentos gelatinosos (22%)... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Previous studies suggest that, apparently, there are specific standards to describe the structure and composition of macroalgae communities in lotic environments depending on the characteristics of the biome to which they belong. In this context, the present study aimed to evaluate, comparatively, the floristic composition, community structure and spatial distribution of lotic macroalgae communities from protected areas (PAs) with two distinct biomes, Grassland on Vila Velha State Park (VVP) and Semideciduous Seasonal Forest on the Iguazu National Park (INP). In addition, we intended to compare the macroalgal communities in the four seasons, to verify the possible existence of temporal patterns. The sampling sites were carried out from five segments of stream, 10 m length, in each PA, by means of the transect technique, where the environmental variables (temperature, oxygen, pH, conductivity, turbidity, depth and current velocity) were measured, as well the presence and abundance of each species of seaweed. These biotic parameters were evaluated using visual analysis of stream/river. The samplings were taken once every season. The taxonomic study recorded 37 macroalgae in total, with 16 taxa occurring exclusively in VVP, 18 taxa occurring exclusively in INP and only three taxa occurring in both parks (Phormidium retzii, Hildenbrand angolensis and Batrachospermum puiggarianum). The taxon with the highest frequency of occurrence in the VVP was Zygogonium sp. (9 sites), whereas in INP "Chantransia" pygmaea is what happened to a greater number of sampled sites (15). Respecting the morphological types were found: free filaments (24%), gelatinous filaments (22%), mats (19%), gelatinous colonies... (Complete abstract click electronic access below)
Mestre

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Estudos anteriores sugerem que, aparentemente, existem padrões específicos para descrever a composição e a estrutura das comunidades de macroalgas em ambientes lóticos em função das características do bioma ao qual estão inseridos. Neste contexto, a presente dissertação objetivou avaliar, de forma comparativa, a composição, a estrutura das comunidades e a distribuição espacial das comunidades de macroalgas lóticas de duas unidades de conservação (UCs) com biomas distintos: Campos no Parque Estadual de Vila Velha (PVV) e Floresta Estacional Semidecidual no Parque Nacional do Iguaçu (PNI). Em adição, pretendeu-se comparar as comunidades de macroalgas nas quatro estações do ano, a fim de se verificar a possível existência de padrões temporais. As amostragens foram realizadas em 5 segmentos de riacho de 10 m de extensão, em cada UC, através da técnica da transeção, onde as variáveis abióticas (temperatura, oxigênio, pH, condutividade, turbidez, profundidade e velocidade da correnteza) foram mensuradas, assim como a presença e a abundância de cada espécie de macroalga. Estes parâmetros bióticos foram avaliados através da análise visual do leito do rio/riacho. As amostragens foram feitas uma vez a cada estação do ano. O estudo taxonômico registrou 37 macroalgas no total, sendo 16 táxons de ocorrência exclusiva no PVV, 18 táxons de ocorrência exclusiva no PNI e apenas 3 táxons com ocorrência em ambos os parques (Phormidium retzii, Hildenbrandia angolensis e Batrachospermum puiggarianum). O táxon com maior ocorrência no PVV foi o Zygogonium sp. (9 ocorrências), e no PNI o estágio “Chantransia” pygmaea foi o que ocorreu em maior número de pontos amostrados (15). Em relação aos tipos morfológicos, foram encontrados: filamentos livres (24%), filamentos gelatinosos (22%)...
Previous studies suggest that, apparently, there are specific standards to describe the structure and composition of macroalgae communities in lotic environments depending on the characteristics of the biome to which they belong. In this context, the present study aimed to evaluate, comparatively, the floristic composition, community structure and spatial distribution of lotic macroalgae communities from protected areas (PAs) with two distinct biomes, Grassland on Vila Velha State Park (VVP) and Semideciduous Seasonal Forest on the Iguazu National Park (INP). In addition, we intended to compare the macroalgal communities in the four seasons, to verify the possible existence of temporal patterns. The sampling sites were carried out from five segments of stream, 10 m length, in each PA, by means of the transect technique, where the environmental variables (temperature, oxygen, pH, conductivity, turbidity, depth and current velocity) were measured, as well the presence and abundance of each species of seaweed. These biotic parameters were evaluated using visual analysis of stream/river. The samplings were taken once every season. The taxonomic study recorded 37 macroalgae in total, with 16 taxa occurring exclusively in VVP, 18 taxa occurring exclusively in INP and only three taxa occurring in both parks (Phormidium retzii, Hildenbrand angolensis and Batrachospermum puiggarianum). The taxon with the highest frequency of occurrence in the VVP was Zygogonium sp. (9 sites), whereas in INP Chantransia pygmaea is what happened to a greater number of sampled sites (15). Respecting the morphological types were found: free filaments (24%), gelatinous filaments (22%), mats (19%), gelatinous colonies... (Complete abstract click electronic access below)

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Biologia de Fungos, Algas e Plantas, Florianópolis, 2015.
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A poluição é capaz de provocar mudanças na riqueza (diversidade alfa), nas abundâncias e/ou composição (diversidade beta) de comunidades biológicas. A entrada de nutrientes e as mudanças na penetração da luz são processos considerados entre os que afetam o crescimento de macroalgas e impactam a estrutura de comunidades. Esse cenário pode resultar em deslocamento na composição de espécies, com a dominância de algas oportunistas. Este trabalho teve como objetivo a análise das diferenças entre os padrões estruturais de comunidades de macroalgas bentônicas em habitats mais impactados e menos impactados do litoral de Santa Catarina, Brasil, com base na análise de dados coletados durante o verão em diferentes praias. A amostragem quantitativa das algas se deu por raspagem das algas presas às rochas, delimitadas por quadrados de cano de PVC de 30 x 30 cm. Foram coletados nos costões rochosos 15 quadrados por praia. Para cada espécie foi obtida a biomassa seca. No aspecto qualitativo, foram identificadas 52 espécies distribuídas entre os filos Rhodophyta, Chlorophyta e Ochrophyta (considerando apenas a Classe Phaeophyceae). A riqueza e a biomassa variaram significativamente entre as praias. Além disso, considerando apenas a biomassa, foram detectadas diferenças entre os ambientes de acordo com seu grau de impacto, de acordo com a análise de variância. Os efeitos significativos da antropização na estruturação das comunidades algais do litoral norte do estado também foram detectados por meio de uma PERMANOVA. A beta-diversidade presente neste trabalho, representada quantitativamente demonstrou os valores superiores encontrados no ambiente menos impactado, através do número superior de indivíduos por praia, motivada por sua maior biomassa relativa de algas calcárias.

Abstract : The pollution can provide changes in richness (alpha diversity), biomass and general composition (beta diversity) of biological communities. Nutrient entrance and light penetration changes can be considered as the main processes which affect macroalgae growth rates and also impact community structures. This scenario may result in species composition shift, with opportunistic species becoming dominants. This study aimed to analyse the differences in structural patterns of benthic macroalgal communities in different habitats with high or less impact degree in Santa Catarina coast, Brazil, in accordance with data collected in the summer at different beaches. Quantitative sampling of algae was done by complete removal of species attached to rocky shores. The area of sampling was determined by PVC quadrats with 30 x 30 cm. 15 quadrats were collected by beach. 52 species were identified, distributed among phylum Rhodophyta, Chlorophyta and Ochrophyta (only Phaeophyceae Class). Biomass and richness varied significatively among different beaches. If considering only biomass, environments more impacted showed lower biomass than those less impacted (in accordance to ANOVA results). Anthropic effects on algal community structures were detected by PERMANOVA. The quantitative beta-diversity observed in this study showed higher values in less impacted environments, with more individuals per beach, motivated by their highest calcareous species relative biomass.

Nella presente ricerca sono state affrontate due principali tematiche: lo studio della biodiversità delle macroalghe e la valutazione del loro potenziale sfruttamento. L’impiego del DNA barcoding ha permesso di identificare 28 specie, contribuendo all’ampliamento del BOLD Systems (www.boldsystems.org), tra cui due specie criptiche e tre aliene. È stato altresì valutato il potenziale impiego in ambito biotecnologico di alcune specie. Sono stati estratti polisaccaridi solfonati da alghe brune che hanno mostrato un’attività anticoagulante su eritrociti umani maggiore a quella dell’eparina. Inoltre, è stata valutata l’efficacia della clorofilla-c quale colorante per celle fotovoltaiche (DSSC), mostrando un buon rendimento energetico. Dai risultati ottenuti è possibile suggerire come alcune macroalghe della laguna di Venezia possano trovare impiego nell’industria farmaceutica e nel settore delle energie rinnovabili. Inoltre, lo sfruttamento di specie invasive consentirebbe la conversione di un prodotto di rifiuto in una preziosa risorsa, integrandosi in un processo di sviluppo sostenibile
In the present research, I deal with two major topics: biodiversity of macroalgae and their potential exploitation. The use of DNA barcoding allowed to identify 28 species, among which two cryptic and aliens, improving the BOLD Systems (www.boldsystems.org). Furthermore, the biotechnological potential of some species was evaluated. Brown algal sulphate polysaccharides showed anticoagulant activity on human red blood cells higher than heparin. Moreover, the performance of chlorophyll-c as a dye in photovoltaic cells (DSSC) was tested resulting a good energetic efficiency. Obtained results proved that some macroalgae from Venice lagoon might be used in pharmaceutical industry and in renewable energies. Besides, the exploitation of invasive species would allow the conversion of a waste into a valuable resource in the framework of a sustainable development process.

ALVES, Antônio Willame da Silva. Técnicas de maricultura da macroalga vermelha Gracilaria birdiae na praia de Flecheiras, Trairi/Ce: efeito de parâmetros ambientais e climáticos sobre a produção de biomassa e extração de ágar. 2016. 63 f. Dissertação (Mestrado em Bioquímica)-Universidade Federal do Ceará, Fortaleza, 2016.
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The red seaweed Gracilaria birdiae, abundant in Ceará, produce, among other polysaccharides, agar, a ficocolóide of great commercial importance because of its thickening properties, stabilizers and gelling agents. The aim of this study was to evaluate the effect of the climatic and environmental parameters in Flecheiras Beach –Trairi, through the dry and rainy season on the production yield of the biomass of G. birdiae, using conventional Long Line (LL) and Long Line with tubular net (RT) and on the yield of agar extraction from cultured seaweed. The LL technique consisted of 4 modules of 10 mm twisted polystyrene rope and the RT was composed of 4 modules of 0.7 mm nylon tubular net and 7 cm internodes, both of which were kept anchored and suspended on the surface of the column Water by buoys. The initial biomass of G.birdiae used in each module was 1.2 kg. The biomass yield (RB), the Daily Growth Rate (TCD) of the seaweed, the environmental parameters (pH, salinity, N-NH3 / NH4 +, N-NO2-, N-NO3- and PO43-) and the yield of agar were evaluated during the dry seasons (July to December) and rainy (January to June) in periods of cultivation of 30 and 45 days. The climatic parameters (cumulative precipitation and mean wind velocity) of the culture site were supplied monthly by FUNCEME. The highest RB were obtained in the dry season, reaching 0.85 kg m-1 for RT in 45 days of cultivation, as well as the highest TCDs, with a maximum of 5% day-1, despite the high wind speeds observed for this season. The lowest RB and TCD were observed in the rainy season (0.16 kg m-1 and 0.6% day-1 for RT45 respectively). The yields agar extraction of the cultivated seaweed varied between 11 and 20%, but without significant difference, as well as the values of environmental parameters (pH, N-NO3-, PO43-) between dry and rainy seasons. N-NH3 / NH4 + was detected only in the rainy season. Therefore, Flecheiras Beach, Trairi-Ce presented as a potential site for the cultivation of G. birdiae through the LL and RT techniques, reaching commercially viable high RB and TCD, but such indices were significantly influenced by the dry and Rainy season, and alterations and adaptations of the crop structures are necessary to the climatic conditions presented by each season of the year aiming to optimize the production of algal biomass.
A alga marinha vermelha Gracilaria birdiae é abundante no litoral cearense e biossintetiza, dentre outros polissacarídeos, o ágar, um ficocolóide de grande importância industrial devido às suas propriedades espessantes, estabilizantes e gelificantes. O objetivo desse trabalho foi avaliar o efeito dos parâmetros climáticos e ambientais das estações seca e chuvosa da Praia de Flecheiras-Trairi/CE sobre o rendimento de produção da macroalga agarófita G. birdiae, através das técnicas de Long Line convencional (LL) e Long Line com rede tubular (RT) e sobre o rendimento da extração de ágar das algas cultivadas. A técnica LL foi constituída por 4 módulos de corda de poliestileno torcida de 10 mm e a RT foi composta por 4 módulos de rede tubular de nylon de 0,7 mm e espaço entrenós de 7 cm, ambas mantidas ancoradas e suspensas na superfície da coluna d´agua por boias. A biomassa inicial de G.birdiae utilizada em cada módulo foi de 1,2 kg. O rendimento de biomassa (RB), a Taxa de Crescimento Diário (TCD) da alga, os parâmetros ambientais (pH, salinidade, N-NH3/NH4+, N-NO2-, N-NO3- e PO43-) e o rendimento de ágar da alga cultivada foram avaliados durante as estações seca (julho a dezembro) e chuvosa (janeiro a junho) em períodos de cultivo de 30 e 45 dias. Os parâmetros climáticos (precipitação acumulada e velocidade média dos ventos) do sítio de cultivo foram fornecidos mensalmente pela FUNCEME. Os maiores RB foram obtidos na estação seca, alcançando 0,85 Kg m-1 para RT em 45 dias de cultivo, assim como as maiores TCDs, com máxima de 5% dia-1, apesar das altas velocidades dos ventos observadas para essa estação. Já os menores RB e TCD foram observados na estação chuvosa (0,16 Kg m-1 e 0,6% dia-1 para RT45 respectivamente). Os rendimentos de extração de ágar (AGb) das algas cultivadas variaram entre 11 e 20%, porém sem diferença significativa, assim como os valores dos parâmetros ambientais (pH, N-NO3-, PO43-) entre as estações seca e chuvosa. N-NH3/NH4+ foi detectada apenas na estação chuvosa. Portanto, a Praia de Flecheiras, Trairi-Ce se apresentou como um sítio potencial para o cultivo de G. birdiae através das técnicas LL e RT, alcançando altos RB e TCD, viáveis comercialmente, porém, tais índices sofreram influência significativa das estações seca e chuvosa, sendo necessárias alterações e adequações das estruturas de cultivo às condições climáticas apresentadas por cada estação do ano visando otimizar a produção de biomassa algácea.

Les macroalgues rouges possèdent un large panel de molécules d’intérêt pour différents domaines d’applications. Cette étude porte sur une espèce non-indigène des côtes françaises, Grateloupia turuturu, en vue d’intensifier sa liquéfaction pour l’extraction de ses composés et en particulier celle d’un pigment d’intérêt, la R-phycoérythrine (R-PE). Trois procédés d’extraction ont été étudiés : l’extraction assistée par hydrolyse enzymatique (EAE), par ultrasons (UAE) et par ultrasons et hydrolyse enzymatique (UAEH). Pour ce faire, quatre complexes enzymatiques de polysaccharidases industrielles et un générateur d'ultrasons tubulaire ont été utilisés. Dans un premier temps, l’efficacité de ces trois procédés, à 40 °C, a été évaluée par la liquéfaction de l’algue. Cette étude a montré que le couplage (UAEH) permet la liquéfaction la plus importante de l’algue, avec plus de 90 % de matière solubilisée. Il a ensuite été décidé de poursuivre cette étude avec l’UAE et l’UAEH. La comparaison de ces deux procédés, à 22 et 40 °C, a montré que l’UAEH était le procédé le plus efficace pour l’extraction de la R-PE et la liquéfaction de l’algue. Il a également été démontré que l’UAEH à 22 °C était préférable pour la R-PE tandis qu’une température de 40 °C favorisait la liquéfaction de G. Turuturu. La relative stabilité de la R-PE aux ultrasons a également été démontrée. Pour finir, l’étude de différents paramètres de l’UAEH (débit, température et puissance) a permis d’optimiser la liquéfaction de G. Turuturu et l’extraction de la R-PE. Les résultats de ce travail de thèse démontrent l’intérêt du couplage ultrasons-enzymes dans l’extraction des composés de G. Turuturu
Red seaweeds contain a large range of molecules of interest for different applications. This study concerns a non-native species of the French coast, Grateloupia turuturu, with a view to intensify its liquefaction for the extraction of its compounds, more particularly a pigment of interest, the R-phycoerythrin (R-PE). Three extraction methods were studied: enzymatic assisted extraction (EAE), ultrasound-assisted extraction (UAE) and ultrasoundassisted enzymatic hydrolysis (UAEH). Four industrial enzymatic preparations of carbohydrases and an ultrasonic flow-through reactor were used. First, the three processes efficiency, at 40 °C, was estimated by the liquefaction of seaweeds. This study demonstrated that the combination (UAEH) allows to obtain the highest liquefaction rate of seaweed, with more than 90 % of solubilized material. It was then decided to continue this study with the UAE and the UAEH. A comparison between the two processes, at 22 and 40 °C, demonstrated that the UAEH was the most efficient for the R-PE extraction and the liquefaction of seaweed. It was also demonstrated that the UAEH at 22 °C was preferable for the R-PE, whereas for the liquefaction of G. Turuturu the best temperature was 40 °C. The relative stability of R-PE towards the ultrasound was also demonstrated. To finish, the study of different UAEH parameters (flow, temperature and power) has allowed to optimize the liquefaction of G. Turuturu and the extraction of R-PE. These thesis results demonstrate the interests of this combination ultrasound-enzymes for the extraction of G. Turuturu compounds

Burgeoning dependence on fossil fuels for transport and industrial sectors has been posing challenges such as depletion of fossil fuel reserves, enhanced greenhouse gas (GHG) footprint, and imminent changes in the climate, etc. Fossil fuels are regarded as unsustainable and questionable from economic, ecology and environmental point of view. Therefore, the pursuit for an environmentally benign and sustainable source of energy started with the advent of oil crisis in 1970, major focus of energy policies shifted to biofuel production from renewable resources. Biofuels minimizes the fossil fuel burning and CO2 production, as it is produced from biomass such as plants or organic waste, thereby decreasing the dependence on oil. The review on evolution of biofuel production from first to second-generation feedstock revealed that the process requires higher concentration of chemical usage due to the presence of lignin. In addition, this feedstock requires arable land and freshwater source for their large-scale cultivation. Recent studies on biofuels indicate that algal biomass; particularly from marine macroalgae (or seaweeds) have the potential to supplement oil fuel Macroalgae with higher concentration of varied carbohydrates (constituting as a source of energy) are emerging as a potential and renewable feedstock towards sustainable biofuel production due to their higher growth rate and availability. Macroalgal biomass cultivation with biorefinery approaches not only aid in empowering rural women with the better economic prospects, but also aid in addressing strategic energy security of the nation. Ceasing of cultivation of salt tolerant paddy and recurring losses with the prawn cultivation (due to viral diseases); have forced abandoning of gazni lands, which can now be used for large-scale cultivation of macroalgae. Macroalgae biomass with higher composition of carbohydrates is relatively higher in gazni, ponds compared to natural rocky shores. In addition, harvesting of algal feedstock in gazni ponds is economical compared to sparsely distributed macroalgae in rocky stretches of the region. Biorefinery approach of macroalgae and macroalgal cultivation for this purpose in Aghanashini estuary could be a good income-generating proposition for the fishermen as well as aid in empowering coastal women

Alkali metals (potassium and sodium) are usually present as inorganic salts or organic-associated elements in biomass and are major contributors to bed agglomeration. This thesis investigated interactions between quartz sand and wood doped with individual alkali salts, together with the effects of Ca and P on such interactions. The interactions behaviours of several agricultural residues and macroalgae with different compositions of alkali salts, Ca and P were assessed. The effect of the reaction atmosphere was also evaluated. All the tests were conducted in a lab-scale, fixed-bed reactor at 900 °C under either a steam gasification (50% v/v steam) or a combustion (5% v/v O2) atmosphere, respectively. Techniques, including scanning electron microscope in combination with energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), acid digestion, water leaching and Atomic Absorption Spectrophotometer (AAS) analyses, were applied. Significant bed agglomerates were observed for wood doped with alkali carbonate, acetate or sulfate, especially during steam gasification. In contrast, the formation of alkali silicates was much lower for alkali chloride-doped wood, especially during combustion, when only insignificant agglomerates were formed. The reactions between gaseous alkali metals and quartz sand contributed to the agglomerates’ formation, especially for K salts. The formation of alkali silicates in the agglomerates decreased significantly with the increase of Ca content, while molten alkali phosphate ash formed agglomerates via a melting-induced mechanism. The co-existence of Ca and P generated K-Ca phosphates, and the influence of the K-Ca phosphates on the interaction behaviours and the K retention in agglomerates varied significantly with the K salts species. Compared with the combustion atmosphere, steam exacerbated bed agglomeration for the coating-induced mechanism but not for the melting-induced mechanism. Steam affected biomass ash-quartz sand interactions both by increasing the alkali metals’ retention and the fractions of alkali silicates with high melting points in the agglomerates and by facilitating the gas-solid phase reactions. The interaction behaviours of several agricultural residues and macroalgae were consistent with those of individual alkali salt-doped wood. A high P and low Ca content in Oedogonium intermedium (ODN) resulted in the co-existence of both melting-induced and coating-induced mechanisms. Fuel-derived molten alkali silicates formed the wheat straw agglomerates via a melting-induced mechanism. For grape marc, cotton stalk and Derbesia tenuissima (Deb), alkali metals reacted with Si in the quartz sand to form agglomerates, with K-Ca phosphates distributed within these agglomerates. Steam significantly increased the size of the grape marc and Deb agglomerates. Except for Deb during combustion, the size of the agglomerates of the tested biomass increased significantly by increasing the reaction time under both atmospheres. This thesis contributes to the comprehensive understanding of biomass ash-quartz sand interactions for various types of biomass with different inorganic compositions during steam gasification or combustion.
Thesis (Ph.D.) -- University of Adelaide, School of Chemical Engineering and Advanced Materials, 2020

Brown macroalgae or brown seaweed is a promising source of ethanol that may avoid the challenges of arable land use, water use, lignin content, and the food vs. fuel debate associated with first generation and cellulosic ethanol sources; however, this promise is challenged by seaweed’s high water content, high ash content, and natural composition fluctuations. Notably, lifecycle studies of seaweed ethanol are lacking in the literature. To address this gap, a well-to-wheel model of ethanol production from farmed brown seaweed was constructed and applied to the case of Saccharina latissima farming in British Columbia (BC), Canada, to determine energy return on energy invested (EROI), carbon intensity (CI), and near shore seaweed farming production potential for seaweed ethanol and to examine the production cost of seaweed ethanol. Seaweed farming and ethanol production were modeled based on current BC farming methods and the dry grind corn ethanol production process; animal feed was included as an ethanol co-product, and co-product credits were considered. A seaweed ethanol yield calculation tool that accounts for seaweed composition was proposed, and a sensitivity study was done to examine case study data assumptions. In the case study, seaweed ethanol had lower CI than sugarcane, wheat, and corn ethanol at 10.1 gCO2e/MJ, and it had an EROI comparable to corn ethanol at 1.78. Seaweed ethanol was potentially profitable due to significant revenue from animal feed sales; however, the market for seaweed animal feed was limited by the feed’s high sodium content. Near shore seaweed farming could meet the current demand for ethanol in BC, but world near shore ethanol potential is likely an order of magnitude lower than world ethanol production and two orders of magnitude lower than world gasoline production. Composition variation and a limited harvest season make solar thermal or geothermal seaweed drying and storage necessary for ethanol production in BC. Varying seaweed composition, solar thermal drying performance, co-product credits, the type of animal feed produced, transport distances, and seaweed farming performance in the sensitivity study gave an EROI of over 200 and a CI of -42 gCO2e/MJ in the best case and an EROI of 0.64 and CI of 33 gCO2e/MJ in the worst case. Co-product credits and the type of animal feed produced had the most significant effect overall, and the worst cases of seaweed composition and solar thermal seaweed drying system performance resulted in EROI of 0.64 and 1.0 respectively. Brown seaweed is concluded to be a potentially profitable source of ethanol with climate benefits that surpass current ethanol sources; however, additional research into seaweed animal feed value, co-product credits, large scale seaweed conversion, and the feasibility of solar thermal or geothermal seaweed drying is required to confirm this conclusion.
Graduate

碩士
國立中山大學
海洋生物研究所
89
Temporary changes in macroalgal abundance, percentage cover and areal biomass were surveyed on Nanwan (GPS: 21o56'00'N; 120o50'10'E) and Tiaoshi (GPS: 21o55'30'N; 120o 50'40'E) reefs (Kenting, Taiwan, Republic of China), during 1999-2000. Community structure and areal biomass showed significant changes in time and the maximal biomass was observed during March-April due to Sargassum spp. at Nanwan and Codium spp. at Tiaoshi. The maximal total areal biomass is not different between two years for Nanwan but significantly different for Tiaoshi mainly due to a marked biomass of Codium edule during 2000. Eutrophication on Nanwan and Tiaoshi reefs is the main cause for macroalgal blooming. Tissue composition analysis, nutrient enrichment and starvation treatments, bioassay and in situ extracellular alkaline phosphatase activity determination showed that growth of Sargassum duplicatum, Codium edule and Ulva latuca were limited by phosphorus during the early growth period while nitrogen during the fast growth period. Growth of Enteromorpha linza, Gracilaria coronopifolia and Laurencia papillosa were limited by phosphorus. Water temperature is the factor affecting the time for the start of development of young shoots and also for the peak of areal biomass and subsequent die-off of thallus. This investigation suggests that the reduction of water nutrient levels is an effective way in the retardation of over-growth of macroalgae on Nanwan and Tiaoshi reefs.

Renewable sources of thermal and chemical energy are needed in order to satisfy the world’s ever growing energy needs while limiting the rise of global temperatures below 2 °C above pre-industrial levels. Plant biomass is a vast resource which if harnessed properly could help revolutionise the global energy economy. Hydrothermal Carbonisation (HTC) is a technology wherein biomass exposed to subcritical water at 180 °C – 260 °C is thermochemically converted into an energy-dense “hydrochar” with strong thermal and elemental similarities to fossil coal. However, key aspects of the HTC reaction remain unknown, especially with regard to the degradation of the key biochemical macromolecules hemicellulose, cellulose, lignin and protein. In this thesis, three novel biomasses, Australian saltbush, hemp and macroalgae, were subjected to HTC and the hydrochars analysed for fuel properties and biochemical composition. The breakdown of the key macromolecules was then described using kinetic modelling to build a mechanistic model of the overall conversion of biomass to hydrochar. Each of the three biomasses underwent profound chemical changes during the HTC reaction, resulting in much lower oxygen content, and much higher carbon content. This caused the energy content of the hydrochars to rise to levels that rivaled or even exceeded those observed in fossil lignites. In addition, the ash content of the biomass was reduced, although certain reaction conditions at higher intensities saw the reabsorbence of inorganic elements back into the char. A twin-pathway mechanistic model was adapted and developed from the literature to describe the overall HTC process and the formation of two different kinds of hydrochar: Mechanism 1, involving solid phase conversions that yield “primary char” derived directly from undissolved and partially converted starting material; and Mechanism 2, a two-step pathway that involves the degradation of the feedstock into dissolved intermediates, and the subsequent repolymerisation of those intermediates into “secondary char”. Using this model as a framework of the backdrop of the HTC reaction, the kinetics of the degradation step in each macromolecule where then analysed in detail. There were numerous broad similarities in the behaviour of the key macromolecules between the different biomasses, in spite of their different origins. The degradation of polysaccharides was determined mainly by the degree of crystallinity; non-crystalline hemicellulose degraded very quickly in every biomass in a pseudo-first order reaction, often being completely eliminated from the feedstock within minutes. On the other hand, highly crystalline cellulose was more recalcitrant, and the reaction orders and rates of degradation of cellulose varied considerably across the three biomasses, although it was consistently slower than its non-crystalline counterparts. Variations in the degree of crystallinity in both cellulose and hemicellulose appeared to result in dramatic differences in the degradation kinetics. Lignin was found to be partially susceptible to HTC degradation, with the majority being dissolved with similar kinetics to hemicellulose, and the remainder being inert. The mechanism of the degradation of protein in macroalgae was opaque and difficult to model, with proteins possibly undergoing Maillard reactions with carbohydrates. It is hoped that the methods presented here, especially regarding the biochemical analyses of the hydrochars, can form a major facet of future research and industrial development of HTC.
Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2020

碩士
國立中山大學
海洋生物研究所
93
Temporal variations of macroalgal cover and biomass (wet weight and dry weight) abundance and assemblage structure, and also the relationships between abiotic factors and assemblage structure, were studied in northeastern Taiwan (GPS: 25o06’80”N; 121o54’60”E）during 2001-2003. This study also investigated the causes affecting Gelidium natural resource and its management. Twenty-seven families with 67 species (5 families with 13 species for Chlorophyta, 3 families with 8 species for Phaeophyta, 19 families with 46 species for Rhodophyta) were recorded. The dominant species such as Pterocladiella capillacea and Polyopes polyideoides belong to temperate species. Macroalgal coverage, areal biomass, diversity, eveness and assemblage structure during 2001-2003 showed significant temporal changes with year and seasonal variations; however, the seasonal rhythm is changing between years. The seasonal pattern is different between 2001 and 2002/2003, biomass peaked in spring of 2002 and 2003. Pterocladiella capillacea, Polyopes polyideoides, Marginisporum crassissimum, Jania ungulate and Chondrus ocellatus contribute to temporal variations in assemblage structure. The results of multi-variate and uni-variate analysis suggest significant temporal variations in macroalgal assemblage structure in northeastern Taiwan, and the data from ANOSIM and SIMPER analysis demonstrated that the seasonal pattern was variable between years, in which it is coincident with seasonal variations in macroalgal abundance. Water temperature, summer high temperature, winter low temperature, nutrient and typhoon are attributable to temporal variations in macroalgal assemblage structure. Low temperature in winter, nutrient availability, and also typhoon restrict the natural resource of Gelidium in northeastern Taiwan; it is hypothesized that low P condition together with enhanced collection deep the decline of Gelidium resource, finally limiting the recovery of Gelidium population in next year. We found that the agar contents of Pterocladiella capillacea showed year and season variations with a negative relationship to biomass. Temporal fluctuations in agar contents was enhanced by low temperatures and high P but decreased by high N. Based on the observations, we conclude that over-collection in winter results in a decline of Gelidium resource in the coming years, thus it could be suggested that winter collection has to be controlled to maintain the sustainable utilization of Gelidium in northeastern Taiwan.