João Inácio Soletti

Ouricuri (Syagrus coronata) fiber: a novel biosorbent to remove methylene blue from aqueous solutions

In this work, the potential of ouricuri (Syagrus coronata) fiber as a novel biosorbent to remove methylene blue (MB) from aqueous solutions was investigated. The fiber was prepared and characterized according to the fundamental features for adsorption. A 23 experimental design was used to evaluate the effects of adsorbent dosage (M), fiber diameter (D) and agitation (A) on the adsorption capacity. In the more adequate conditions, kinetic and equilibrium studies were performed. The experimental design results showed that M = 10 g L-1), D = 0.595 mm and A = 200 rpm were the more adequate conditions for MB adsorption. Based on the kinetic study, it was found that the adsorption process was fast, being the equilibrium was attained at about 5 min, with 90% of color removal. The isotherm was properly represented by the Sips model, and the maximum adsorption capacity was 31.7 mg g-1. In brief, it was demonstrated that ouricuri fiber is an alternative biosorbent to remove MB from aqueous media, taking into account the process efficiency and economic viewpoint.

Optimal routing offshore helicopter using Genetic Algorithm

This With the discovery of oil in the Pre-Salt layer, in oceanic regions of Brazil, it is aroused the need to improve technological devices of analysis, to ensure the sustainability of the system of fuel production in the country. From there we conjecture about the problem of air traffic control of offshore helicopters, which give logistical support to oil platforms and to optimization of routes. In this paper, we propose to minimize routes, thus decreasing the fuel consumption of these aircraft, as well as to optimize the time spent on travel between airports and platforms, using the heuristics methods of Genetic Algorithms.

Adsorption of methylene blue on agroindustrial wastes: Experimental investigation and phenomenological modelling

In this work, agro-wastes coming from soursop (peel, seeds and pulp fiber) and sugarcane (bagasse) are used as low-cost biosorbents to remove methylene blue (MB) from aqueous media. Batch experiments are performed under different experimental conditions investigating the effects of biosorbent amount, dye concentration and stirring rate. The best results were found using soursop wastes for a MB concentration of 100 mg L-1, using 0.75 g of residue and a stirring rate of 110 rpm, removing a percentage above 90%. Theoretically, adsorption kinetic can be successfully described by the pseudo-second order model. Redlich-Peterson and Sips models are adopted to interpret the equilibrium adsorption of MB on sugarcane bagasse and soursop residue, respectively. Interestingly, the monolayer model with single energy derived by statistical physics theory is also applied for a deeper explanation of the adsorption mechanism of MB on both the adsorbents. The application of this model allows defining the adsorption geometry of the investigated adsorbate and provides important information about the interactions between the adsorbate and sorbents. In particular, the modelling analysis by statistical physics allows defining that the dye molecules are adsorbed in vertical position and the adsorption process is multi-molecular (i.e. n > 1). Finally, the estimation of adsorption energy suggested that MB adsorption on biosorbent is a physisorption process.

INFLUÊNCIA DA TEMPERATURA NOS RENDIMENTOS DOS PRODUTOS DA PIRÓLISE DO ENDOCARPO DO OURICURI (SYAGRUS CORONATA (MART) BECC.)

O licuri ou ouricuri, Syagrus coronata (Mart) Becc., e uma palmeira cuja distribuicao se estende ate o litoral brasileiro, cresce bem nas restingas baianas, mas tem preferencia pelas regioes de caatinga, crescendo em areas altamente pedregosas e castigadas pelo sol, ate outras com melhores condicoes de solo, tornando-se parte da vegetacao predominante de algumas regioes. Um estudo realizado em Buique (PE), mostrou que a importância do ouricuri esta relacionada predominantemente ao uso da amendoa. Como forma de aproveitar o endocarpo (material lignificado que envolve a amendoa), este trabalho objetiva o estudo da pirolise do endocarpo do ouricuri, agregando valor, por meio da geracao de produtos com potencial comercial. Avaliou-se o rendimento dos produtos obtidos para diferentes temperaturas finais (400, 500, 600 e 700oC), com taxa de aquecimento de 10oC/min e o tempo de residencia de 2h (duas horas), alem de vacuo constante de 50mmHg, para controlar a atmosfera do reator, evitando queima. Com o aumento de temperatura, o rendimento em carvao diminuiu devido a decomposicao dos constituintes do endocarpo. Por sua vez o rendimento em gases foi crescente com o aumento da temperatura e o rendimento da mistura liquida aumentou na faixa de 400oC a 600oC, mas decresceu a temperatura de 700oC, devido ao craqueamento dos vapores condensaveis.

TRATAMENTO DE UM EFLUENTE DA INDÚSTRIA DO COCO EM UNIDADE PILOTO DE FLOTAÇÃO POR AR DISSOLVIDO (FAD)

Este trabalho propoe estudar a aplicacao de tecnicas de sistemas de separacao, mais especificamente a flotacao por ar dissolvido, aplicadas ao tratamento de efluentes liquidos com contaminacao de oleo e/ou solidos em suspensao de uma industria local de processamento de coco. A flotacao por ar dissolvido e um processo consagrado em nivel mundial para o tratamento de agua e de efluentes industriais. A flotacao e um processo pelo qual ha remocao de particulas, liquidas ou solidas, de uma fase liquida, por meio da introducao de bolhas de gas, as quais aderem a superficie dessas particulas formando aglomerados de densidade menor que a agua, que ascendem a superficie, de onde serao removidas. Nesse presente trabalho foram estudados 3 tipos de coagulantes, sulfato de aluminio, sulfato de ferro e policroleto de aluminio (PAC), e um polimero anionico. Foi observado que o poli cloreto de aluminio se destacou entre os 3 coagulantes, apresentando desempenho superior aos outros dois utilizados, tanto em relacao a clarificacao do efluente quanto ao tempo de resposta apos sua adicao. Com a flotacao por ar dissolvido foi possivel reduzir o TOG em ate 87,4% e a DQO ate 81,8%.