Alginate and Sericin: Environmental and Pharmaceutical Applications

Alginate is a polysaccharide that, for commercial purposes, is extracted exclusively from marine brown algae. In this chapter, we discuss the main sources of alginate and sodium alginate manufacturing, its chemical structure and physicochemical properties, the alginate modifications, and blend formation. We also present applications of alginate and sericin blend in the pharmaceutical and environmental fields as well as case studies

Ion Exchange Fundamentals and New Challenges

Ion exchange is a stoichiometric phenomenon commonly used in water treatment as an end-of-pipe technique. Such process is highly influenced by mass transfer conditions and may be modeled by adsorption equations. Although widely applied in industries its theory has not been completely understood and depends on the exchanger characteristics. Moreover, competitive systems may add complexity and decrease removal efficiency and exchanger selectivity mainly in dynamic systems. In this chapter some general theory was presented and some detailed examples involving alginate biopolymer, bonechar and zeolite in single and competitive systems were discussed in batch and continuous state

Desenvolvimento de unidade experimental de leite fluidizado circulante para o estudo do processo de remoção de SO2 na combustão de carvão mineral com a adição de calcario

Orientador: Leonardo Goldstein JrTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia MecanicaResumo: Este trabalho consistiu no desenvolvimento de um reator de leito fluidizado circulante, para operar nas codições de fluidização rápida, visando sua utilização em processo de combustão de carvão mineral com remoção do 802' pela adição de calcário. o desenvolvimento desse estudo foi realizado em três etapas. A primeira se constituiu no levantamento e análise dos processos de desulfurização dos gases de combustão e dos parâmetros de projeto do equipamento. A segunda,foi o projeto, construção e montagem do sistema experimental. A terceira foi a partida e a pré-operação da unidade, com a realização de um programa de testes a frio e a quente para o conhecimento da operacionalidade e da flexibilidade do sistema projetado. o dispositivo experimental é constituidode três partes principais: o combustor propriamente dito, com 4,0 m de altura e 0,1m de diâmetro interno; a seção de retorno de sólidos e a seção de resfriamento dos gases de combustão. O sistema é composto ainda por dois alimentadores pneumáticos de sólidos, um sistema de preaquecimento elétrico do ar de fluidização, um queimador de G.L.P. e um filtro manga com limpeza por jato pulsante. Foram realizados 42 testes experimentais com particulas sólidas de areia, com 0,2mm de diâmetro, dos quais 19 foram desenvolvidos com ar primário e 23 com a injeção de ar secundário. Foram variados durante a operação o inventário de sólidos, de 3,0 a 11,0kg, e velocidade do ar de fluidização, de 3,0 a 18,0m/s, em temperaturas até 750°CAbstract: The present work is centered on the development of a circulating fluidized bed reactor to be operated in conditions of quick fluidization, aiming its utilization in mineral coal combustion process with remotion of 5°2 by adding limestone. The developing of this study was carried out in three stages. The first part consisted of raising and analysis of the sulfurization of combustion gases process and the parameters of the design of the equipment. The second included designing, building and assembling of the experimental system. The third was the start and preoperation of the unit, along with a'program of tests, cold and hot, in order to determine the conditions of operation and flexibility of the designed system. The experimental device is consisted of there main parts: the combustion itself,with dimensionsof 4.0m. in height and 0,1m. of internal diameter; a solid return section and the section of cooling of combustion gases. The system still has two solid pneumatic feeders, an eletrical pre-heating system for the fluidization air a G.L.P. burner and a sleeve filter with pulsing set cleaning. A total of 42 experimental tests were carried out with solid particles of sand, 0,2mm. in diameter, of which 19 were developed with primary air and 23 with the injection of secondary air. A variation of solids mass was made, from 3.0 to 11.0 kg and the air velocity, from 3.0 to 18.0 m/s and with temperature up to 750°CDoutoradoTermica e FluidosDoutor em Engenharia Mecânic

Dinamica do transporte pneumatico vertical de particulas

Orientador: Cesar Costapinto SantanaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de CampinasResumo: No presente trabalho, foram realizados estudos experimentais acompanhados de formulações matemáticas sobre a queda de pressão no escoamento de mistura ar-sólidos em sistema vertical. Foram incluídos nestes estudos a dinâmica de uma região de aceleração, bem como a da região de escoamento completamente desenvolvido. Baseando-se em equações de conservação da mas sa e quantidade de movimento em sistemas particulados foi proposto um método de previsão de queda de pressão nas regiões de escoamento acima mencionadas, envolvendo o cálculo da poros idade, velocidades do fluido e das partículas e o comprimento de entrada. Os resultados obtidos desses parâmetros foram comparados com de outros procedimentos previstos na literatura. No desenvolvimento deste trabalho foi estabelecida ainda, uma correlação semi-empírica para o coeficiente que expressa o atrito dos sólidos com a parede do tubo, analisando-a com outras existentes na literatura. Os dados experimentais foram obtidos em um sistema vertical de 4,0 m de altura e 0,05m de diâmetro, com partículas sólidas de 0,_24; 0,40; 1,0; 1,2 e 1,7mm de diâmetro médio e com a mesma densidade, sendo realizadas cerca de 242 determinações experimentais, das quais 69 foram efetuadas na região de escoamento estabelecido e,173 foram incluída a região de aceleração. Estas determinações acrescidas de um conjunto de dados da literatura, permitiram analisar a consistência das formulações e equações propostas para o cálculo dos parâmetros que descrevem a dinâmica do escoamento gás-sólido vertical em fase diluída.Abstract: In the present experimental work studies were made with mathematical formulations on pressure drop on an air-solids vertical flow system. Both the dynamics of the acceleration region and the completely developed flow were included in the mentioned studies. The equations of continuity and movement in particulated systems were taken as the basis of this work and a method of estimating the pressure drop in the two regions was proposed, which involved the calculation of the porosity, local velocities of fluid and particles and the entry length. The results obtained for these parameters were compared with some other methods cited in the literature" As a development of this work it was established a semi-empirical correlation for the particle-wall friction factor. The experimental data were obtained for a vertical flow system of 4.0m of length and 0.05m of diameter including particles with mean diameter of 0.24, 0.40, 1.0, 1:2 and 1.7mm,all having the same specific gravity. About 242 experimental determinations were made, 69 of which for the completely developed flow and the other 173 for the acceleration region. These experimental determinations added to a set of data found in the literature allowed the verification of the proposed formulations and equations for calculating the parameters describing the dynamics of a gas-solid vertical flow in diluted phase.MestradoMestre em Engenharia Químic

Cadmium biosorption by alginate extraction waste and process overview in Life Cycle Assessment context

This work evaluated the cadmium biosorption capacity by the alginate extraction residue from brown seaweed Sargassum filipendula, an industry waste which is often discharged into the sea. The biosorption kinetics and equilibrium were investigated, with further analysis of the process thermodynamics. The Mass Transfer in External Film model best described the kinetic data and the rate controlling step is the diffusion through the boundary layer. The kinetic constant values of the model were 0.129, 0.064 and 0.066 1/min for initial concentrations of 1.0, 1.5 and 2.0 mmoL/L, respectively. The isotherms were obtained at four temperatures (293, 303, 313 and 323 K) and were analyzed by Langmuir, Freundlich and Dubinin-Radushkevich models. The system was better described by Freundlich model, and the Dubinin-Radushkevich model suggested that the cadmium uptake is of physical nature. The maximum biosorption capacity obtained at 293 and 303 K were 0.394 and 0.429 mmoL/g, respectively. The thermodynamic parameters indicated that the biosorption of cadmium is spontaneous and exothermic. The simplified LCA showed that the use of dealginated residue would lead to lower environmental impacts for Acidification, Climate Change, Eutrophication, Human Toxicity and Photochemical Oxidation178166175FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2014/05050-

Equilibrium, Thermodynamic, Reuse, and Selectivity Studies for the Bioadsorption of Lanthanum onto Sericin/Alginate/Poly(vinyl alcohol) Particles

In a scenario of high demand, low availability, and high economic value, the recovery of rare-earth metals from wastewater is economically and environmentally attractive. Bioadsorption is a promising method as it offers simple design and operation. The aim of this study was to investigate lanthanum bioadsorption using a polymeric bioadsorbent of sericin/alginate/poly(vinyl alcohol)-based biocomposite. Batch system assays were performed to evaluate the equilibrium, thermodynamics, regeneration, and selectivity of bioadsorption. The maximum capture amount of lanthanum at equilibrium was 0.644 mmol/g at 328 K. The experimental equilibrium data were better fitted by Langmuir and Dubinin–Radushkevich isotherms. Ion exchange mechanism between calcium and lanthanum (2:3 ratio) was confirmed by bioadsorption isotherms. Thermodynamic quantities showed that the process of lanthanum bioadsorption was spontaneous (−17.586, −19.244, and −20.902 kJ/mol), endothermic (+15.372 kJ/mol), and governed by entropic changes (+110.543 J/mol·K). The reusability of particles was achieved using 0.1 mol/L HNO3/Ca(NO3)2 solution for up to five regeneration cycles. The bioadsorbent selectivity followed the order of lanthanum > cadmium > zinc > nickel. Additionally, characterization of the biocomposite prior to and post lanthanum bioadsorption showed low porosity (9.95 and 12.35%), low specific surface area (0.054 and 0.019 m2/g), amorphous character, and thermal stability at temperatures up to 473 K. This study shows that sericin/ alginate/poly(vinyl alcohol)-based biocomposites are effective in the removal and recovery of lanthanum from water