New and effective cassava bagasse-modified biochar to adsorb Food Red 17 and Acid Blue 9 dyes in a binary mixture.

A promissory technic for reducing environmental contaminants is the production of biochar from waste reuse and its application for water treatment. This study developed biochar (CWb) and NH4Cl-modified biochar (MCWb) using cassava residues as precursors. CWb and MCWb were characterized and evaluated in removing dyes (Acid Blue 9 and Food Red 17) in a binary system. The adsorbent demonstrated high adsorption capacity at all pH levels studied, showing its versatility regarding this process parameter. The equilibrium of all adsorption experiments was reached in 30 min. The adsorption process conformed to pseudo-first-order kinetics and extended Langmuir isotherm model. The thermodynamic adsorption experiments demonstrated that the adsorption process is physisorption, exhibiting exothermic and spontaneous characteristics. MCWb exhibited highly efficient and selective adsorption behavior towards the anionic dyes, indicating maximum adsorption capacity of 131 and 150 mg g-1 for Food Red 17 and Acid Blue 9, respectively. Besides, MCWb could be reused nine times, maintaining its original adsorption capacity. This study demonstrated an excellent adsorption capability of biochars in removing dyes. In addition, it indicated the recycling of wastes as a precursor of bio composts, a strategy for utilization in water treatment with binary systems. It showed the feasibility of the reuse capacity that indicated that the adsorbent may have many potential applications.

Means of communication for visually impaired people. Fractalyphlotechnologies of data communication

This article describes technical means of data communication for blind and visually impaired people. Radically new method of haptic and fingerspelling data coding is proposed based on fractal self-similarity of binary code. It would be possible to develop numerous typhlo-appliances at reasonable and low price, thus simplifying teaching Braille system both in conventional, manual, and computer variants. Coding of typhlodata on the basis of fractal self-similarity is referred to as fractal Braille. On the basis of fractal self-similarity of binary code, the concept of haptic and fingerspelling alphabet has been developed which combines essentially different methods of data coding in a single morphological base.

Adsorción competitiva de Ni (II) y Pb (II) sobre materiales residuales lignocelulósicos

Introducción: Un estudio batch fue realizado para la adsorción de Pb (II) y Ni (II) en solución binaria, utilizando biomasas de tusa de maíz y cáscara de naranja. Métodos: Las concentraciones iniciales de cada metal variaron en 25, 50, 75 y 100 ppm. La adsorción se llevó a cabo a pH 6,0 y tamaño de biomasas de 0,5 mm. Las mediciones de concentración residual de los metales se determinaron por absorción atómica. Resultados: Se encontró que la concentración inicial del metal y las soluciones binarias no interfieren en el porcentaje de remoción de los contaminantes, y que los modelos Freundlich y Langmuir ofrecen un buen ajuste de los datos experimentales. Conclusión: Se estableció que la acción antagonista de los metales cambia de acuerdo a la biomasa utilizada, siendo la capacidad del Ni (II) > Pb (II) para la tusa de maíz, y Pb (II) > Ni (II) para las cáscaras de naranja.

Introduction: A batch study was carried out for the adsorption of Pb (II) and Ni (II) in binary solution using biomasses from corncob and orange peel. Methods: The initial concentrations of each metal were varied in 25, 50, 75 and 100 ppm. The adsorption was conducted at pH 6.0 and biomass size of 0.5 mm. Measurements of residual metal concentrations were determined by atomic absorption. Results: It was found that the initial metal concentration and binary solutions not interfere with the removal percentage of the contaminants, and the Freundlich and Langmuir models provided a good fit of the experimental data. Conclusion: It was also established that the metal antagonistic action changes according to the biomass used, being the capacity of Ni (II)>Pb (II) for the corncob biomass, and Pb (II)> Ni (II) for the orange peels.

Introdução: Foi feito um estudo batch para a adsorção de Pb (II) e Ni (II) em solução binária, utilizando biomassas de espiga descascada de milho e casca de laranja. Métodos: As concentrações iniciais de cada metal variaram em 25, 50, 75 e 100 ppm. A adsorção foi feita a pH 6,0 e tamanho de biomassas de 0,5 mm. As medições de concentração residual dos metais se determinaram por absorção atómica. Resultados: Encontrou-se que a concentração inicial do metal e as soluções binárias não interferem na porcentagem de remoção dos contaminantes, e que os modelos Freundlich e Langmuir oferecem um bom ajuste dos dados experimentais. Conclusão: Estabeleceu-se que a ação antagónica dos metais muda de acordo com a biomassa utilizada, sendo a capacidade do Ni (II) > Pb (II) para a espiga de milho e Pb (II) > Ni (II) para as cascas de laranja.