Academic literature on the topic 'Algal Flocculation'
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Journal articles on the topic "Algal Flocculation"
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Matter, Bui, Jung, Seo, Kim, Lee, and Oh. "Flocculation Harvesting Techniques for Microalgae: A Review." Applied Sciences 9, no. 15 (July 29, 2019): 3069. http://dx.doi.org/10.3390/app9153069.
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Microalgae have been considered as one of the most promising biomass feedstocks for various industrial applications such as biofuels, animal/aquaculture feeds, food supplements, nutraceuticals, and pharmaceuticals. Several biotechnological challenges associated with algae cultivation, including the small size and negative surface charge of algal cells as well as the dilution of its cultures, need to be circumvented, which increases the cost and labor. Therefore, efficient biomass recovery or harvesting of diverse algal species represents a critical bottleneck for large-scale algal biorefinery process. Among different algae harvesting techniques (e.g., centrifugation, gravity sedimentation, screening, filtration, and air flotation), the flocculation-based processes have acquired much attention due to their promising efficiency and scalability. This review covers the basics and recent research trends of various flocculation techniques, such as auto-flocculation, bio-flocculation, chemical flocculation, particle-based flocculation, and electrochemical flocculation, and also discusses their advantages and disadvantages. The challenges and prospects for the development of eco-friendly and economical algae harvesting processes have also been outlined here.
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Kwak, Dong-Heui, and Mi-Sug Kim. "Estimation and evaluation of auto-flocculated algae harvesting efficiency using the population balance in turbulence model in flotation process." Water Science and Technology 77, no. 5 (September 21, 2017): 1165–78. http://dx.doi.org/10.2166/wst.2017.491.
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Abstract Algae are considered water pollutants because they form algal blooms in stagnant water. Algae harvesting technology, however, can help convert them into a useful industrial material like biomass. The core technique (flocculation) separates microalgae from other flocculants, allowing for the harvest of clean and pure algal biomass. This study aims to estimate and evaluate algal separation (removal or harvesting) efficiency (X) to concurrently obtain the objectives of algal bloom management and algal particle collection. To simulate algal separation by auto-flocculation (no flocculants) related flotation, the population balance in turbulence (PBT) model is used. Model simulations are conducted under optimal conditions provided by previous studies about the biological impact factors of algae, operating parameters of the flotation process, and so on. This modeling study determines the efficiency (X) of separating algae from the water body in the separation zone after forming auto-flocculated bubble–floc agglomerates by making them collide and attach to each other in the contact zone of the flotation tank. The X is examined as a function of size distribution of agglomerates and bubbles and of the number of initially injected bubbles. Optimal conditions for forming and harvesting the agglomerates may be found through further modeling studies.
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Ayoub, George M., Sang-Ill Lee, and Ben Koopman. "Seawater induced algal flocculation." Water Research 20, no. 10 (October 1986): 1265–71. http://dx.doi.org/10.1016/0043-1354(86)90157-0.
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Pieterse, A. J. H., and A. Cloot. "Algal cells and coagulation, flocculation and sedimentation processes." Water Science and Technology 36, no. 4 (August 1, 1997): 111–18. http://dx.doi.org/10.2166/wst.1997.0099.
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Flocculation generally removes two classes of suspended particles during adsorption-coagulation, namely colloids (inorganic in nature) and bacterial and algal cells, colonies, and filaments (organic in nature). Different interaction mechanisms, i.e. hydrodynamic, electrical and electromagnetic, play important roles in the removal of algal and colloidal entities. Algal entities, however, show morphological characteristics (such as elongated shapes, arranged in cells, colonies and filaments, containing spines or able to change shape or to move with flagella) not shared by colloids, that will affect the flocculation of the algal cells. If algal cells are globally in equilibrium with themselves, it is possible that the negative surface charge of algal cells will be restored after charge neutralisation. In addition to Van der Waals forces, affecting the coagulation of colloidal and algal entities, the flocculation of algal entities may also be affected by gravitation forces (because of larger sized algal entities) and forces created in the immediate vicinity of the cells by metabolic processes such as photosynthesis and respiration.
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Elmaleh, S., J. Coma, and J. Borsato. "Algal Flocculation in a Magnesium Exchanger Fluidized Bed." Water Science and Technology 26, no. 7-8 (October 1, 1992): 1689–96. http://dx.doi.org/10.2166/wst.1992.0612.
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The effectiveness of the microalgae flocculation by a fluidized bed of magnesium exchanger resin particles was investigated. The results indicated that the total suspended solids abatement could reach 90% at pH 11.5 while the superficial upflow velocity was 30 m/h which corresponds to a residence time through the flocculator less than 1 minute. The abatement remains steady even after exhaustion of the ion exchange capacity while the bed is continuously expanding which makes the resin regeneration easy and lowers the magnesium requirement. The extracted sludge is easily thickened. The destabilized suspension is itself easily concentrated by sedimentation followed by single draining.
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Wang, Mingyong, Bowen Zhang, Xihua Cao, Fang Li, Xiuxian Song, and Zhiming Yu. "Influence of Algal Organic Matter on Algal Removal Efficiency by Flocculation of Modified Clay." Journal of Marine Science and Engineering 11, no. 3 (March 14, 2023): 613. http://dx.doi.org/10.3390/jmse11030613.
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Modified clay (MC) technology is the most effective method to control harmful algal blooms (HABs) and has been widely testified in many countries in recent decades. Although dissolved algal organic matter (dAOM) has been found to be abundant in HAB-affected waters, little is known about its effect on MC flocculation. Prorocentrum donghaiense was chosen as the model organism in this study. The flocculation of MC with different concentrations of dAOM was observed by particle image velocimeter, and the removal efficiency of MC to microalgae was determined using a fluorometer. The results showed that a small amount of dAOM resulted in faster flocculation, larger flocs, higher floc strength and better floc regeneration capacity, and the removal efficiency of microalgae by MC could reach about 80%. However, large amounts of dAOM produced during the occurrence of HABs could inhibit the flocculation of MC, and the removal efficiency of microalgae was only about 35%. Furthermore, with the increase of dAOM, the zeta potential of MC particles decreases from 1.56 mV to −18.9 mV, and the repulsive force between the particles also increases. The examination of 18-angle laser light scattering gel permeation chromatography and specific ultraviolet absorption (SUVA254) revealed that some hydrophobic organic macromolecules preferred to attach to MC and increase MC flocculation at a tiny amount of dAOM, while a higher concentration of dAOM would inhibits flocculation by reducing surface activity and intergranular repulsion. According to the findings of this study, the dosage of MC must be increased in order to obtain the best algal removal efficiency with MC.
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Yahi, H., S. Elmaleh, and J. Coma. "Algal flocculation-sedimentation by pH increase in a continuous reactor." Water Science and Technology 30, no. 8 (October 1, 1994): 259–67. http://dx.doi.org/10.2166/wst.1994.0421.
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The effectiveness of microalgae flocculation by pH increase was investigated using the jar test procedure. The results indicated that pH values between 11.8 and 12 induced extensive flocculation without need of adding magnesium. pH was increased by sodium hydroxide or calcium hydroxide. In both cases, the total solids abatement was more than 95% producing sludge of excellent settleability and good mechanical resistance quantified by a destructive test. The next step was the operation of a continuous flocculator which might optionally be packed with granular sand or inert resin. It was shown that a fluidized bed or any other mechanical energy transfer device was not required to obtain more than 95% efficiency with a superficial upflow velocity of 30 m/h corresponding to a residence time through the whole unit of 5 minutes only.
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Craggs, R. J., S. Heubeck, T. J. Lundquist, and J. R. Benemann. "Algal biofuels from wastewater treatment high rate algal ponds." Water Science and Technology 63, no. 4 (February 1, 2011): 660–65. http://dx.doi.org/10.2166/wst.2011.100.
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This paper examines the potential of algae biofuel production in conjunction with wastewater treatment. Current technology for algal wastewater treatment uses facultative ponds, however, these ponds have low productivity (∼10 tonnes/ha.y), are not amenable to cultivating single algal species, require chemical flocculation or other expensive processes for algal harvest, and do not provide consistent nutrient removal. Shallow, paddlewheel-mixed high rate algal ponds (HRAPs) have much higher productivities (∼30 tonnes/ha.y) and promote bioflocculation settling which may provide low-cost algal harvest. Moreover, HRAP algae are carbon-limited and daytime addition of CO2 has, under suitable climatic conditions, the potential to double production (to ∼60 tonnes/ha.y), improve bioflocculation algal harvest, and enhance wastewater nutrient removal. Algae biofuels (e.g. biogas, ethanol, biodiesel and crude bio-oil), could be produced from the algae harvested from wastewater HRAPs, The wastewater treatment function would cover the capital and operation costs of algal production, with biofuel and recovered nutrient fertilizer being by-products. Greenhouse gas abatement results from both the production of the biofuels and the savings in energy consumption compared to electromechanical treatment processes. However, to achieve these benefits, further research is required, particularly the large-scale demonstration of wastewater treatment HRAP algal production and harvest.
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Ma, Wei, Chenchen Feng, Fachun Guan, Dianrong Ma, and Jinling Cai. "Effective Chlorella vulgaris Biomass Harvesting through Sulfate and Chloride Flocculants." Journal of Marine Science and Engineering 11, no. 1 (December 29, 2022): 47. http://dx.doi.org/10.3390/jmse11010047.
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Efficient microalgae harvesting is a great challenge hindering diverse industrial applications of microalgae. Flocculation is regarded as an effective and promising technology for microalgae harvesting. In this study, sulfate (Al2(SO4)3 and Fe2(SO4)3) and chloride flocculants (AlCl3 and FeCl3) were used to harvest Chlorella vulgaris. Flocculation conditions, including flocculant dose, flocculation time, stirring speed, stirring time, and flocculation pH, were optimized, and flocculant effects on microalgal cell status, floc characteristics, biomass composition, algal cell re-culture, and media recycling were investigated. All flocculants exhibited efficient flocculation efficiency (93.5–98.8%) with lower doses of sulfate salts (60 mg/L algal culture) and higher doses of chloride salts (100 mg/L algal culture). The tested flocculants had no obvious influence on biomass composition (including lipids, carbohydrates, proteins, and carotenoids), and microalgal cells in flocs could efficiently regrow. The spent medium of all treatments was successfully recycled for subsequent cell growth, thus reducing dependency on fresh medium.
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Lee, S. I., B. Koopman, and E. P. Lincoln. "Effect of Physicochemical Variables on Algal Autoflotation." Water Science and Technology 26, no. 7-8 (October 1, 1992): 1769–78. http://dx.doi.org/10.2166/wst.1992.0620.
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Combined chemical flocculation and autoflotation were examined using pilot scale process with chitosan and alum as flocculants. Positive correlation was observed between dissolved oxygen concentration and rise rate. Rise rate depended entirely on the autoflotation parameters: mixing intensity, retention time, and flocculant contact time. Also, rise rate was influenced by the type of flocculant used. The maximum rise rate with alum was observed to be 70 m/h, whereas that with chitosan was approximately 420 m/h. The efficiency of the flocculation-autoflotation process was superior to that of the flocculation-sedimentation process.
Dissertations / Theses on the topic "Algal Flocculation"
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Rhea, Nicholas A. "Evaluation of Flocculation, Sedimentation, and Filtration for Dewatering of Algal Biomass." UKnowledge, 2016. http://uknowledge.uky.edu/bae_etds/42.
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Algae can be used as a feedstock for agricultural fertilizers, livestock/poultry feeds, anaerobic digestion, and biofuel production. Regardless of the end product, water removal is necessary and difficult to do cost effectively. For each product the requirements for moisture content (or solids content) vary, such that a desirable water removal strategy would need to be adaptable to varying levels of water removal. Flocculation, with sedimentation and drying was evaluated as a possible strategy for algae dewatering. Anionic and nonionic flocculants are known to be ineffective at flocculating algal culture, which was confirmed for this case by electro-osmotic flow testing of the algae and jar tests with three flocculant charge types. Electrophoretic mobility of the algae indicated that it has a negative charge and no flocs were present in the jars. The effectiveness of the cationic flocculant was determined by measuring settling rates, supernatant turbidity, and filtration rates. Sedimentation and filtration rates of Scenedesmus acutus were measured with varying dosages (0-25 ppm) of a synthetic cationic polymeric flocculant. The results of this study should assist in predicting the time it takes to thicken algae at a concentration range of 0.4-1.0 g/L to a product at a concentration range of 15-250 g/L.
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Scholz, Matthew John. "Microbial Cogeneration of Biofuels." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/145446.
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The fields of biodiesel and bioethanol research and development have largely developed independently of one another. Opportunities exist for greater integration of these processes that may result in decreased costs of production for both fuels.To that end, this work addresses the use of the starches and glycerol from processed algal biomass as substrates for fermentation by the yeasts
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Hansel, Philip A. "Efficient Flocculation of Microalgae for Biomass Production Using Cationic Starch." Ohio University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1313779752.
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Filho, Paulo Luiz Centurione. "Desenvolvimento e operação de uma instalação de flotação de bancada para águas de abastecimento." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-06122016-104835/.
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Tendo em vista a potencialidade da remoção de algas utilizando a flotação por ar dissolvido, foi proposto o desenvolvimento de um equipamento de laboratório de fácil operação e manutenção, denominado Floteste, integrando as características geométricas do equipamento Jarteste neste trabalho. Foram realizados ensaios, utilizando água sintética contendo algas da ordem de 108 ind/L e natural proveniente de curso d\'água eutrofizado, possibilitando o aprimoramento do estudo das condições de coagulação, mistura rápida, floculação e flotação. Também, ensaios de flotação seguida de filtração em areia foram feitos visando melhorar a qualidade da água flotada. O jarro do Floteste possui placa de orifícios que proporciona perda de carga suficiente para a distribuição uniforme de água saturada pela seção quadrada do mesmo. Concluiu-se que, principalmente, que a dosagem de coagulante e o respectivo pH de coagulação, tempo e gradiente de velocidade médio de mistura rápida, tempo e gradiente de velocidade médio de floculação, tempo e pressão de saturação e a quantidade de ar fornecido exercem influência significativa na remoção de algas, turbidez, cor verdadeira e do número de partículas nos dois tipos de águas estudadas.Due to the potentiality of the algae removal by dissolved air flotation, it was proposed the development of an equipment in laboratory scale of easy operation and maintenance, dominated Floteste, integrating the geometric characteristics of the Jarteste equipment in this work. Tests were carried out with synthetic water containing a high concentration of algae (~108 ind/L) and natural water from and eutrophicated source. Besides several improvements in the equipment developed in this study, the rapid mixing can be considered the most important, followed by flocculation and flotation. Also, flotation and sand filtration tests were performed to simulate the floto-filtration technology. The Flotateste vessel have a perforated plate that provides enough loss of load in order to uniform the distribution of saturated water in the bottom. It was concluded, mainly, that the coagulant dose and the pH of coagulation, time and velocity gradient of rapid mixing, time and velocity gradient of flocculation, time and saturation pressure chamber and the amount of air supplied played a significant role in the removal of algae, turbidity, true color and of the number of particles in the two types of water studied.
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Paz, Júnior Gilberto José da [UNESP]. "Uso de floculador hidráulico de manta de lodo acoplado a flotador por ar dissolvido no tratamento de água de abastecimento." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/98069.
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Novas tecnologias para o tratamento de água vêem sendo desenvolvidas e suas combinações podem apresentar bons resultados principalmente quando submetidas a variações sazonais de origem natural e antropicas. A crescente poluição dos corpos d’água causa florescimentos de algas e cianobactérias nos mananciais, com aparecimento de sabor e odor na água bruta, podendo ocorrer também a liberação de toxinas pelas cianobactérias. Os processos de tratamento de água convencionais têm apresentado deficiências quanto à remoção de cianobactérias e cianotoxinas, principalmente quanto ao aspecto de remoção das células viáveis e na capacidade de remover as toxinas extracelulares. As cianobactérias retidas no lodo dos decantadores representam riscos à qualidade final da água tratada. O presente projeto de pesquisa consistiu em experiência com floco-decantador de manta de lodo acoplado a flotador por ar dissolvido, formando um conjunto composto pelos dois tipos de equipamentos ou tecnologias e ainda com dispositivo limitador de manta. O objetivo da pesquisa foi avaliar o desempenho da instalação proposta quando submetida a variações da qualidade da água bruta, principalmente quando submetido à sobrecarga de algas e cianobactérias, simulando possíveis florações nos mananciais. Os resultados dos ensaios no modulo experimental com água natural apresentaram remoção satisfatória de turbidez , com valores abaixo de 3,0 uT da água floco-floto-decantada e em torno de 0,1 uT da água filtrada. Os ensaios realizados com água natural com presença elevada de algas e cianobactérias, evidenciaram a importância da unidade de flotação, com remoção de clorofila_a de 82% na água decantada/flotada e próximo de 99% na água filtrada, em relação à água bruta, sendo que a turbidez manteve-se abaixo de 3 uT na saída do modulo floco-floto-decantador e a turbidez...
New technologies for water treatment have been developed and their combinations can produce good results especially when subjected to seasonal variations of natural and anthropogenic. The increasing pollution of water bodies causes blooms of algae and cyanobacteria in water sources, with the appearance of taste and odor in raw water, but may also occur the release of toxins by cyanobacteria. The processes of conventional water treatment have shown deficiencies in the removal of cyanobacteria and cyanotoxins, especially on the aspect of removal of viable cells and the ability to remove extracellular toxins. Cyanobacteria retained in the sludge of the sedimentation tanks pose to the final quality of treated water. This research project was to experiment with floc-settling sludge blanket coupled to dissolved air flotation, forming a group composed of two types of equipment or technology, and with relief device blanket. The research aimed to evaluate the performance of the proposed development when subjected to variations in raw water quality, especially when subjected to the overload of algae and cyanobacteria to simulate possible blooms in the springs. The results of tests on an experimental module with natural water showed satisfactory removal of turbidity, with values below 3 uT decanted and around 0,1 uT filtered water. Tests conducted with water with high presence of algae and cyanobacteria, have highlighted the importance of unity flotation Chlorophyll “a” with removal of 82% in the decanted water / rappel and around 99% in filtered water compared to raw water, and the turbidity remained below 3 uT the output of modulo-flake-floto sedimentation and turbidity of filtered water was below 0,6 uT. The limiting device of the ground and periodic removal of sludge, decreased the retention time of the cells retained in the sludge which may have prevented the release of toxins into the water... (Complete abstract click electronic access below)
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Paz, Júnior Gilberto José da. "Uso de floculador hidráulico de manta de lodo acoplado a flotador por ar dissolvido no tratamento de água de abastecimento /." Ilha Solteira : [s.n.], 2009. http://hdl.handle.net/11449/98069.
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Orientador: Edson Pereira TangerinoBanca: Dib Gebara
Banca: Carlos Gomes da Nave Mendes
Resumo: Novas tecnologias para o tratamento de água vêem sendo desenvolvidas e suas combinações podem apresentar bons resultados principalmente quando submetidas a variações sazonais de origem natural e antropicas. A crescente poluição dos corpos d'água causa florescimentos de algas e cianobactérias nos mananciais, com aparecimento de sabor e odor na água bruta, podendo ocorrer também a liberação de toxinas pelas cianobactérias. Os processos de tratamento de água convencionais têm apresentado deficiências quanto à remoção de cianobactérias e cianotoxinas, principalmente quanto ao aspecto de remoção das células viáveis e na capacidade de remover as toxinas extracelulares. As cianobactérias retidas no lodo dos decantadores representam riscos à qualidade final da água tratada. O presente projeto de pesquisa consistiu em experiência com floco-decantador de manta de lodo acoplado a flotador por ar dissolvido, formando um conjunto composto pelos dois tipos de equipamentos ou tecnologias e ainda com dispositivo limitador de manta. O objetivo da pesquisa foi avaliar o desempenho da instalação proposta quando submetida a variações da qualidade da água bruta, principalmente quando submetido à sobrecarga de algas e cianobactérias, simulando possíveis florações nos mananciais. Os resultados dos ensaios no modulo experimental com água natural apresentaram remoção satisfatória de turbidez , com valores abaixo de 3,0 uT da água floco-floto-decantada e em torno de 0,1 uT da água filtrada. Os ensaios realizados com água natural com presença elevada de algas e cianobactérias, evidenciaram a importância da unidade de flotação, com remoção de clorofila_a de 82% na água decantada/flotada e próximo de 99% na água filtrada, em relação à água bruta, sendo que a turbidez manteve-se abaixo de 3 uT na saída do modulo floco-floto-decantador e a turbidez... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: New technologies for water treatment have been developed and their combinations can produce good results especially when subjected to seasonal variations of natural and anthropogenic. The increasing pollution of water bodies causes blooms of algae and cyanobacteria in water sources, with the appearance of taste and odor in raw water, but may also occur the release of toxins by cyanobacteria. The processes of conventional water treatment have shown deficiencies in the removal of cyanobacteria and cyanotoxins, especially on the aspect of removal of viable cells and the ability to remove extracellular toxins. Cyanobacteria retained in the sludge of the sedimentation tanks pose to the final quality of treated water. This research project was to experiment with floc-settling sludge blanket coupled to dissolved air flotation, forming a group composed of two types of equipment or technology, and with relief device blanket. The research aimed to evaluate the performance of the proposed development when subjected to variations in raw water quality, especially when subjected to the overload of algae and cyanobacteria to simulate possible blooms in the springs. The results of tests on an experimental module with natural water showed satisfactory removal of turbidity, with values below 3 uT decanted and around 0,1 uT filtered water. Tests conducted with water with high presence of algae and cyanobacteria, have highlighted the importance of unity flotation Chlorophyll "a" with removal of 82% in the decanted water / rappel and around 99% in filtered water compared to raw water, and the turbidity remained below 3 uT the output of modulo-flake-floto sedimentation and turbidity of filtered water was below 0,6 uT. The limiting device of the ground and periodic removal of sludge, decreased the retention time of the cells retained in the sludge which may have prevented the release of toxins into the water... (Complete abstract click electronic access below)
Mestre
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Bracharz, Felix R. [Verfasser], Thomas [Akademischer Betreuer] Brück, Thomas [Gutachter] Brück, and Wolfgang [Gutachter] Liebl. "Screening and Characterization of Oleaginous Yeasts and Modeling of Flocculation-based Algae Harvest / Felix R. Bracharz ; Gutachter: Thomas Brück, Wolfgang Liebl ; Betreuer: Thomas Brück." München : Universitätsbibliothek der TU München, 2017. http://d-nb.info/1181946662/34.
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Cerski, Erika Reesink. "Estudo de separação de algas cultivadas em uma lagoa de alta taxa no tratamento de efluentes sanitários por coagulação-floculação e flotação por ar dissolvido com ênfase na estabilidade do material flotado." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/156477.
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A separação de microrganismos fotossintetizantes no tratamento de efluentes possui dois aspectos fundamentais. O primeiro refere-se à qualidade do efluente tratado e seu impacto sobre os recursos hídricos e, o segundo, refere-se ao potencial deste material como fonte de energia renovável. Diversos trabalhos tem demostrado elevada eficiência na separação de algas no tratamento de efluentes. Entretanto, quando considerado o cultivo de microalgas para utilização da biomassa como matéria prima, para produção de biocombustível por exemplo, mais estudos científicos são necessários. Entre as operações de separação sólido-líquido, normalmente empregadas no tratamento de efluentes, a flotação por ar dissolvido tem se mostrado uma tecnologia vantajosa, pois, além de ser capaz de separar partículas com diâmetro reduzido e baixa velocidade de sedimentação, também permite a obtenção de um material flotado com maior percentual de sólidos, desejável para redução dos custos de processamento da biomassa algal. O objetivo deste trabalho foi avaliar a separação de microalgas cultivadas em uma lagoa de tratamento de esgoto de alta taxa através do processo de coagulação-floculação e flotação por ar dissolvido. Como contribuição aos estudos de separação por FAD, foi avaliado a estabilidade do material flotado submetido a uma agitação mecânica, utilizando a técnica de captura e análise de imagens digitais, segundo um parâmetro chamado porcentagem de área (αa) Este parâmetro é definido como o percentual de pixels pretos em relação ao total de pixels da imagem, e demonstra a instabilidade do material flotado. Os coagulantes cloreto férrico e Tanfloc SG (Tanac®) e os floculantes sintéticos do tipo poliacrilamidas (SNF Floerger®) catiônico (FO4550SH), aniônico (FA920SH) e não iônico (FA920SH) foram investigados em diferentes dosagens e combinações. O presente estudo mostrou que a separação de algas através deste sistema é viável tecnicamente, sendo que os melhores resultados apresentaram uma remoção de turbidez de 92% para a combinação de cloreto férrico (20mg/L) + FO4550SH (2mg/L) e 97% para Tanfloc SG (20mg/L) + AN956SH (1mg/L). Em relação à estabilidade do material flotado, as amostras que continham apenas coagulantes apresentaram valores de αa entre 4,26 e 5,49, indicando uma baixa estabilidade do material flotado. Enquanto as combinações de cloreto férrico (20mg/L) + FO4550SH(0.5mg/L) e Tanfloc SG (20mg/L) +FO4550SH (1 e 2mg/L) foram as que produziram um material flotado com maior estabilidade, apresentando αa=0,35 e αa=0,40, respectivamente, demonstrando que o uso dos polímeros proporciona uma maior estabilidade do material flotado, quando este está sujeito a turbulências.Separation of photosynthetic microorganisms in the effluent treatment has two fundamental aspects. The first refers to the quality of the treated effluent and its impact on water resources, and the second refers to the potential of this material as a source of renewable energy. Several studies show high efficiency in the separation of algae in effluent treatment. However, more scientific studies are required considering the cultivation of microalgae for the use of them as a raw material for biomass, like biofuel for instance. Among solid-liquid separation operations normally employed in effluents treatment, dissolved air flotation has been shown to be an advantageous technology in order to separate algae, because allows not only the separation of particles with reduced diameter and low sedimentation velocity, but also produces a floating material with higher percentage of solids, which is desirable for reducing the processing costs of the algal biomass. The aim of this work was to evaluate the separation of microalgae originated on a high rate pond through the coagulation, flocculation and dissolved air flotation (DAF) processes. As a contribution to the DAF separation studies, the stability of the floating material was evaluated against mechanical agitation, using the technique of digital image analysis, according to a parameter called area percentage (αa) This parameter is defined as the percentage of pixels in relation to the total pixels of the image, and demonstrates the instability of the floating material. The ferric chloride and Tanfloc SG (Tanac®) coagulants and the synthetic flocculants polyacrylamide types (SNF Floerger®) cationic (FO4550SH), anionic (FA920SH) and nonionic (FA920SH) were investigated in different concentrations and combinations. The present study showed that algae separation through this system is technically feasible. The best results showed a turbidity removal of 92% for the combination of ferric chloride (20mg/L) + FO4550SH (2mg/L) and 97% for Tanfloc SG (20mg/ L) + AN956SH (1mg/L). In relation to the stability of the floated material, the samples containing only coagulants presented values of αa between 4.26 and 5.49, indicating a low stability of the floated material. While the ferric chloride (20mg / L) + FO4550SH (0.5mg / L) and Tanfloc SG (20mg / L) + FO4550SH (1 and 2mg / L) combinations were the ones that produced a floated material with greater stability, 0.35 and α = 0.40, respectively, demonstrating that the use of the polymers provides greater stability of the floated material when it is subjected to turbulence.
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Kaloudis, Dimitrios. "Improving microalgae for biofuel production." Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.665443.
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Microalgae are a diverse group of oxygenic photosynthetic microorganisms which show great promise as a source of biofuel. However, significant challenges still remain before microalgae can be considered a viable source of biofuel. The main current challenges are nutrient sourcing and recycling as well as downstream processing. The algal cell wall and especially the presence of an algaenan cell wall in some Chlorophyte algae could be an important variable in determining downstream processing costs but not much comparative research has been done to elucidate this. The first part of the present study focuses on the recently isolated alga Pseudochoricystis ellipsoidea (Trebouxiophyceae) and its improvement and assessment for biofuel production. Random mutagenesis and FACS screening protocols were developed for the isolation of pigment and cell wall mutants but despite considerable efforts no suitable mutants could be identified in the first half of this project. Two 500 L raceway ponds as well as an algal growth room and bubble column bioreactors were set up to facilitate algal research at the University of Bath and assess the performance of P. ellipsoidea in realistic culture conditions. P. ellipsoidea showed a maximum growth of 1.53 divisions day-1 in semi-open raceway ponds, resistance to contamination and a 30% lipid content, making it particularly suitable for raceway pond cultures. In the second part of this project six species of Chlorophyte (“green”) algae, three of which produced algaenan, were compared for suitability to growth in anaerobic digestate and municipal wastewater as well as cell wall strength, permeability and suitability to hydrothermal liquefaction. We found that anaerobic digestate was a good medium for the growth of all species independently of autoclaving and that non-autoclaved wastewater was a very challenging medium. Algaenan production did not affect cell disruption by ultrasonication but growth stage and cell wall thickness did. Lipid extraction kinetics by chloroform/methanol were greatly affected by algaenan, meaning that this material is relatively impermeable to organic solvents. Cell wall thickness, cell volume and lipid content also had an effect on lipid extraction kinetics but this was only measurable after 180 minutes of extraction. 8 Hydrothermal liquefaction showed high solid and low oil yields, very low sulphur (≤0.1 %) as well as a 1.1 % -1.8 % nitrogen content which is significantly lower than most algal HTL studies to date. This suggests that stationary stage algae are more difficult to process but give a cleaner biocrude and reduce the loss of nitrogen through incorporation in the oil. Significant opportunities for optimisation still exist in the HTL process.
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YEH, YI-TING, and 葉奕廷. "Flocculation of Nannochloropsis Oculata with Algal Sedimentary Symbiotes." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/83fvn6.
Full textBooks on the topic "Algal Flocculation"
Book chapters on the topic "Algal Flocculation"
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Debnath, Surajit. "Characterization of Extracellular Proteins to Explore Their Role in Bio-Flocculation for Harvesting Algal Biomass for Wastewater Treatment." In The Role of Microalgae in Wastewater Treatment, 229–66. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-1586-2_18.
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Khalid, Mehwish, and Imran Hashmi. "Selection of Strains and Breeding of Algae." In Handbook of Research on Algae as a Sustainable Solution for Food, Energy, and the Environment, 58–83. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-6684-2438-4.ch003.
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Intensive research efforts are aimed at increasing and modifying the algal biomass production and selection for different purposes. Financial aspects for biomass production techniques always remain a challenge that needs to be addressed. Using cost-effective media for the growth and choosing high lipid content strain is always aimed to reduce the cost of yield of algal biomass. With each passing day, there is advancement in the use of algae for the vested interests. Different species are expected to function well at different niche and environmental conditions. Therefore, adaptation of robust method and selection of algal trait is most relevant for yielding large scale algal biomass. The overarching significance of producer strain has driven research in recent years towards genetically modified species. This chapter particularly focusses on the selection and breeding of algae like different cultivation aspects in open pond, photobioreactor, bio flocculation, and advantages and disadvantages thereof.
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Chatsungnoen, Tawan, and Yusuf Chisti. "Flocculation and electroflocculation for algal biomass recovery." In Biofuels from Algae, 257–86. Elsevier, 2019. http://dx.doi.org/10.1016/b978-0-444-64192-2.00011-1.
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Yarkent, Cagla, Bahar Aslanbay Guler, Ceren Gurlek, Yaprak Sahin, Ayse Kose, Suphi S. Oncel, and Esra Imamoglu. "Algal Alginate in Biotechnology: Biosynthesis and Applications." In Properties and Applications of Alginates. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.101407.
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Algae are recognized as the main producer of commercial alginate. Alginate produced using algae is located in the walls and intracellular regions of their cells. Its properties vary depending on the species, growing and harvesting seasons, and extraction methods. Alginate has attracted the attention of several industries, thanks to its unique properties such as its biodegradability, biocompatibility, renewability and lack of toxicity features. For example, it is considered a good encapsulation agent due to the transparent nature of the alginate matrices. Also, this biopolymer is recognized as a functional food in the food industry. It can be tolerated easily in human body and has the ability to reduce the risk of chronic diseases. Besides, it is used as an abrasive agent, antioxidant, and thickening and stabilizing agents in cosmetic and pharmaceutic industries. Generally, it is used in emulsion systems and wound dressing patches. Furthermore, this polysaccharide has the potential to be used in green nanotechnologies as a drug delivery vehicle via cell microencapsulation. Moreover, it is suitable to adopt as a coagulant due to its wide range of flocculation dose and high shear stability. In this chapter, the mentioned usage areas of algal alginate are explained in more detail.
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Dutta, Mintu Maan, and Anushmita Charingia. "Nanotechnology-Based Nano-Biosorbents." In Handbook of Research on Emerging Developments and Environmental Impacts of Ecological Chemistry, 386–408. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-1241-8.ch018.
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Most countries worldwide face the problem related to clean and safe water. The major source of contamination of water bodies includes the discharges of wastes from various domestic and industrial sources (heavy metal ions, dyes, and pharmaceuticals). To overcome those problems, various water purification methods such as coagulation, flocculation, adsorption, membrane separation, biological, and electrochemical methods have been engaged. Adsorption using nano-biosorbents based on chitin, chitosan and modified chitosan, cellulose, alginate, micro algal has emerged as a better alternative for the removal of contaminants from drinking and wastewater treatment. The main advantages of these nano-biosorbents include its biodegradability and eco-friendliness, which have attracted researchers to this field.
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Rastogi, Rupali. "Water Purification Using Different Chemical Treatment." In Advances in Environmental Engineering and Green Technologies, 338–67. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-6111-8.ch019.
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Water from surface sources is often contaminated by microbes, whereas groundwater is normally safer, but even groundwater can be contaminated by harmful chemicals from human activities or from the natural environment. The purification process of water may reduce the concentration of particulate matter including suspended particles, parasites, bacteria, algae, viruses, fungi, and a range of dissolved and particulate material derived from the surfaces. Water purification is the process of removing undesirable chemicals, materials, and biological contaminants from contaminated water. Most water is purified for human consumption (drinking water), but water purification may also be designed for a variety of other purposes, such as medical, pharmacology, chemical, and industrial applications. In general, the methods used include physical processes such as filtration and sedimentation, biological processes such as slow sand filters or activated sludge, chemical processes such as flocculation and chlorination, and the use of electromagnetic radiation such as ultraviolet light.
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Kroon, Aart. "Marine and Coastal Environments." In The Physical Geography of Western Europe. Oxford University Press, 2005. http://dx.doi.org/10.1093/oso/9780199277759.003.0016.
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The present coastline of western Europe is shaped by physical processes such as wind, waves, and tidal currents, which cause the marine and coastal sediment transport. Spatial gradients in sediment transport rates induce the morphological adaptation, reflected by either an accumulation or erosion of material. All mutual interactions between these physical processes, and the resultant gradients in sediment transport together with the morphological adaptations, constitute the coastal morphodynamics. The specific initial stage of the morphology and the availability of sediment influence the direction of the morphological adaptation, whereas the rate of the morphological adaptation mostly depends on the energy input into the system. Chemical processes are of less importance in coastal environments of the high to mid-latitudes. Here most geochemical reactions are far too slow to influence the coastal morphology. However, biological processes sometimes play an important role. For example, flocculation of fine sediments by algae in estuaries (Ten Brinke 1993) or filtering by salt-marsh vegetation (Houwing 2000a, b) both positively influence the sediment accumulation rates. The long-term boundary conditions upon which the physical processes act are often determined by geology. The nature of the drainage basin that delivers fresh water and sediments into coastal waters and the nature of the shoreline can be considered as static boundary conditions for short-term morphodynamics. Tectonic forces and global sea-level rise are typical long-term geophysical forces. They will slowly change these boundary conditions, but they hardly influence the short-term adaptations of the morphology. The western European shelf fringes a series of integrated coastal environments that vary from coastal dunes and sandy beaches to estuaries and tidal basins and to sea cliffs and shore platforms. In this chapter a general description of the location and dimensions of the shores of western Europe is presented, followed by a brief summary of its geological history. The geology is focused on present-day deposits, the local lithology with sinks and sources of sediments, and with reference to some geophysical processes such as the relative sea-level rise. Thereafter, the actual coastal processes are discussed.
Conference papers on the topic "Algal Flocculation"
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Zhang, Jin. "Notice of Retraction: Optimization of Coupling Effect of Oxidation and Flocculation in Removal of Algal Pollution with Fenton's Reagent." In 2011 5th International Conference on Bioinformatics and Biomedical Engineering. IEEE, 2011. http://dx.doi.org/10.1109/icbbe.2011.5781018.
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Sharma, Rohan, Scott Shirley, Tahir Farrukh, Mohammadhassan Kavosi, and Myeongsub Kim. "Microalgae Harvesting in a Microfluidic Centrifugal Separator for Enhanced Biofuel Production." In ASME 2020 18th International Conference on Nanochannels, Microchannels, and Minichannels collocated with the ASME 2020 Heat Transfer Summer Conference and the ASME 2020 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/icnmm2020-1078.
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Abstract Biofuel is one of the renewable energy resources alternatives to fossil fuels [1]. Among various sources for biofuels, microalgae provide at least three-orders-of-magnitude higher production rate of biodiesel at a given land area than conventional crop-based methods. However, microalgal biodiesel still suffers from significantly lower harvesting performance, making such a fuel less competitive. To increase the separation performance of microalgae from cultivation solution, we used a spiral microchannel that enables the isolation of biofuel-algae particles from water and contaminants contained in the culturing solution. Our preliminary data show that separation performance in the microfluidic centrifugal separator is as high as 88% within a quick separation time of 30 seconds. To optimize separation performance, multiple parameters of algae behaviors and separation techniques were studied and were manipulated to achieve better performance. We found that changing these factors altered the separation performance by increasing or decreasing flocculation, or “clumping” of the microalgae within the microchannels. The important characteristics of the separator geometry, fluid properties, and environmental conditions on algae separation was found and will be further studied in the forthcoming tests. This introductory study reveals that there is an opportunity to improve the currently low performance of algae separation in centrifugal systems using much smaller designs in size, ensuring a much more efficient algae harvesting.
Reports on the topic "Algal Flocculation"
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Thomas, Catherine C., Jonathan Broussard, and Victor F. Medina. Chitosan as a Coagulant and Precipitant of Algae Present in Backwater. U.S. Army Engineer Research and Development Center, July 2022. http://dx.doi.org/10.21079/11681/44904.
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The purpose of this technical note (TN) is to highlight the current state of knowledge of algal flocculation by chitosan and identify data gaps existing between specific algal characteristics and chitosan binding efficiency. Published relationships and correlations between the quality of backwaters and the prevalence of algae, a baseline for flocculation efficiency of microalgae, and ideal treatment instances for algal removal by way of chitosan flocculation and precipitation will be identified.
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Hewson, John C., Nicholas B. Wyatt, Flint Pierce, Patrick Vane Brady, Brian P. Dwyer, Anne Grillet, Matthew G. Hankins, et al. First-principles flocculation as the key to low energy algal biofuels processing. Office of Scientific and Technical Information (OSTI), September 2012. http://dx.doi.org/10.2172/1090222.
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