Bioremediation is one of the methods to eliminate metallic pollutants from leach mining. Its use provide technical and economical adventages compared to ionic exchange or membranes. In bioacumulation, a type of bioremediation, metal ions are incorporated into microorganism cells, its inconvenient is necessity to prepare cultures media and special conditions to mantain biomass. On the other hand, biosorption uses natural polymers, called biopolymers; functional features of these macromolecules give them metallic adsorption capacity in predetermined conditions; some of them are algae derivatives like alginates, poliamides from hair, colagen from bond tissues or chitin and chitosan extracted from crustaceous shells. Specially chitosan could be obtained from chitin, second most abundant biopolymer in nature next to cellulose, its main source is food industry of prown, shrimp, crab and simila...

Bioremediation is one of the methods to eliminate metallic pollutants from leach mining. Its use provide technical and economical adventages compared to ionic exchange or membranes. In bioacumulation, a type of bioremediation, metal ions are incorporated into microorganism cells, its inconvenient is necessity to prepare cultures media and special conditions to mantain biomass. On the other hand, biosorption uses natural polymers, called biopolymers; functional features of these macromolecules give them metallic adsorption capacity in predetermined conditions; some of them are algae derivatives like alginates, poliamides from hair, colagen from bond tissues or chitin and chitosan extracted from crustaceous shells. Specially chitosan could be obtained from chitin, second most abundant biopolymer in nature next to cellulose, its main source is food industry of prown, shrimp, crab and simila...

El pez Anisotremus scapularis "Chita" es una especie que habita en la costa de Perú y se considera potencial para la acuicultura. Los estudios sobre el perfil de aminoácidos aún no han sido reportados. El objetivo de esta investigación fue desarrollar un método analítico para la cuantificación de aminoácidos en músculo liofilizado de Chita mediante HPLC-FL. Para lograr este objetivo, se optimizaron las condiciones de hidrólisis, resultando una concentración de HCl de 6 M, un tiempo de hidrólisis de 24 horas y una temperatura de 100 °C. Los resultados de los parámetros de rendimiento más relevantes fueron los siguientes: la linealidad presentó un coeficiente de determinación (R2>0,999), la veracidad mostró que todos los aminoácidos no superaron un sesgo del 15%. La recuperación varió del 97,08% al 102,44%. Los coeficientes de variación para la repetibilidad y la p...

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...

La presencia de ácido sulfhídrico (H2S) en el medio ambiente representa un peligro para la salud de las personas. Los métodos convencionales para la detección de H2S requieren del uso de soluciones captadoras, las cuales contienen sulfato de cadmio (CdSO4), hidróxido de sodio (NaOH) y arabinogalactano, que a su vez puede provocar daños en la salud por una constante exposición. En el presente trabajo se validó el uso de polisacáridos Ulvan, como aditivo reemplazante en la preparación de la solución absorbente del contaminante gaseoso ácido sulfhídrico (H2S) según la metodología COVENIN 3571:2000 Calidad de aire. Determinación de la concentración sulfuro de hidrogeno (H2S(g)) en la atmosfera. Los resultados obtenidos en la validación del método modificado (porque se modificó la solución absorbente) fueron analizados a través de parámetros como linealidad, precisión,...

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...

The objective of the present work was to determine the optimal conditions for the coagulation of suspended particles of silver iodide of negative charge by the action of solutions of chitosan, aluminum sulfate and the mixed action of both coagulants. The suspension of colloidal particles of AgI was obtained by mixing diluted solutions of KI and AgNO3 in excess of KI. In all the experiments the volume of the colloidal system was 600 mL and pH= 6. The optimal parameters for the coagulation process were determined based on the Jar Test method. For the chitosan solution the optimal parameters were: concentration 0.01%, pH = 4.5 and a volume of 25 mL; for aluminum sulfate: concentration 30 ppm, pH = 4.0 and volume 25 mL. In the case of the mixed action of both coagulants, the optimal parameters were 5 mL of a 30 ppm solution of aluminum sulfate at pH 4.0 and 20 mL of a 0.01% chitosan solution...