Objetivo: En esta investigación se ha desarrollado un nuevo biosorbente conformado por Thorin (sal sódica del ácido 2-(2-hidroxi-3,6-disulfo-1-naftilazo) bencenarsónico) adsorbido e inmovilizado en quitosano, para la remoción de iones metálicos utilizando como modelo de adsorción al cadmio (Cd2+). Método: Para tal fin, se han estudiado los parámetros más representativos del fenómeno de adsorción, tal como la influencia del pH, experimentos de equilibrio y cinéticos, con el fin de optimizar la adsorción de Thorin en quitosano en polvo y perlas, así como también la inmovilización de este adsorbato primario en la matriz del quitosano mediante un proceso de reticulación con glutaraldehído (QPCR). Resultados: Esta modificación ha permitido la obtención de un adsorbente secundario que luego fue utilizado en la remoción de cadmio (II), formando así un sistema ternario de ...

A polymerized ionic liquid membrane (PILM) has been synthesized by copolymerization of 3-butyl-1-vinylimidazolium bromide with acrylonitrile and then loaded with brilliant yellow dye (AB) describing an anion exchange process. The main objetive of this synthesis is the measurement of pH in aqueous solutions between pH 6,5 and 8,0; close to neutral conditions. Both PILM and PILM-AB membranes were characterized by FT-IR spectroscopy and their pH-response was measured by UV-Vis spectrophotometry.

Biosorption optimal pH and kinetics of lead (II) on Ascophyllum nodosum seaweed at 20°Cwere studied. In order to improve structural stability of alginate and avoid leaching, thebiomass was pre-treated with CaCl2. Biosorption kinetics experimental data showed gratercoefficients of correlation (R2) on pseudo second order mathematic model. Physical chemistryparameters: particle size influence (75 μm - 180 μm and 0 μm - 75 μm) and biosorbent andmetal concentrations in solution were evaluated in the biosorption kinetics. Pseudo secondorder constant, k2 = 1.0x10-4 g.mg-1min-1, of biosorbent with particle size 75-180 μm increasedin 20% as particle size decreased to 0-75 μm, meanwhile, q2e increased from 67,7 to 94,5mg/g at the same conditions. Lead (II) residual concentrations in solution were determinedby atomic absorption spectroscopy. For data processing and statistic treatment of non...

Lead (II) biosorption on Ascophyllum nodosum seaweed at 20°C and initial pH 4-5 wasstudied, by using models of Langmuir and Freundlich isotherms. In order to establishseaweed, CaCl2 was used. The granulometry used in the biosorbent was 0-75 μm. In Fourier transform infrared spectroscopy, FT-IR, a shift in the signal of carbonyl group of crosslinkedsample before metal biosorption and after (1600.92 cm-1 to 1573.91 cm-1) and 1400 cm-1 (thatwas from 1415.75 cm-1 to 1409.96 cm-1) was observed, suggesting a chelating (bidentate)character of the metal biosorption onto carboxylic groups that belongs to the units of alginatemonomeric. The bands at 3305.99 cm-1 allowed the recognition of hydroxyl groups in thebiosorbent. The scanning electronic microscopy, SEM, verified heterogeneity of biosorbentparticles. In the energy-dispersive X-ray spectroscopy, EDAX, a very strong signal in thecarbon and...

Biosorption kinetics of cadmium (II) on cross-linked pectin extracted from orange peels at 20°C was studied, obtaining an equilibrium sorption capacity, q , of 99.56 mg/g in pH range e 4.5-5.5. Pectic material was extracted through acid hydrolysis (pH: 1.5, temperature: 90°C, time: 30 min) and crosslinked with formaldehyde acidic solution in order to diminish hydration capacity and swelling, as well as polysaccharide leaching when found in aqueous environment. Biosorption kinetics experimental data showed greater coefficients of correlation (R ) on pseudo second order mathematic model. Physical chemistry parameters: particle size influence (125 µm - 500 µm and 0 µm - 125 µm) and biosorbent and metal concentrations in solution were evaluated in the biosorption kinetics. Pseudo second order -4 -1 -1 constant, k = 8.0x10 g.mg min , of biosorbent with particle size 125-500 µm increase...