RESUMO
Jute stick powder (JSP) has been found to be a promising material for adsorptive removal of congo red (C.I. 22120) and rhodamine B (C.I. 45170) from aqueous solutions. Physico-chemical parameters like dye concentration, solution pH, temperature and contact time have been varied to study the adsorption phenomenon. Favorable adsorption occurs at around pH 7.0 whereas temperature has no significant effect on adsorption of both the dyes. The maximum adsorption capacity has been calculated to be 35.7 and 87.7mg/g of the biomass for congo red and rhodamine B, respectively. The adsorption process is in conformity with Freundlich and Langmuir isotherms for rhodamine B whereas congo red adsorption fits well to Langmuir isotherm only. In both the cases, adsorption occurs very fast initially and attains equilibrium within 60min. Kinetic results suggest the intra-particle diffusion of dyes as rate limiting step.
Assuntos
Corantes/isolamento & purificação , Vermelho Congo/isolamento & purificação , Extratos Vegetais/química , Rodaminas/isolamento & purificação , Purificação da Água/métodos , Adsorção , Biomassa , Celulose/química , Concentração de Íons de Hidrogênio , Resíduos Industriais , Cinética , Soluções/química , Temperatura , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/químicaRESUMO
Biomass of food yeast Kluyveromyces fragilis (MTCC 188) grown on deproteinized whey supplemented with 0.8% diammonium hydrogen phosphate and 10 ppm indole-3-acetic acid, had a crude protein content of 37%. The true protein content based on nitrogen fractionation procedure was 28.1%. Total nucleic acid content was 4.82%. This amount does not appear to be toxicologically offensive. Crude fiber, ash, and lipid content of K.fragilis dry cells were found to be 4.9%, 16%, and 7.8%, respectively. Essential fatty acids of both omega-3 and omega-6 series were found present in the fat of the yeast and represented 21.5% of the total fatty acids. All the essential amino acids were present in the proteins of K. fragilis; however, sulfur containing amino acids were found in lower amounts. Calculated protein scores indicate moderate biological value. B vitamins in the biomass were present as expected, but folic acid and pyridoxine were present in high concentration.