Využití pomerančové kůry k odstranění šestimocného chromu z vodného prostředí: kinetika, termodynamika, izotermy

Abstract

The kinetics, adsorption isotherms and thermodynamic parameters of the biosorption process of hexavalent chromium onto chemically activated citrus waste peel were studied using batch technique. The thesis contents an introduction to the topic, focuses on biosorption process characteristics, factors that influence the process, chromium behavior in aquaeous solutions and methods of wastewater treatment. Furthermore, the methodology and results of the experiment are described. The citrus peel has been activated using hydrochloride acid of 1 mol l-1 concentration. Samples were analysed by a spectrophotometric method with 1,5-diphenylcarbazide. The most suitable particle size for industrial application appeared to be the size of < 0,5 mm at exposition time 40 min. Langmuir and Freundlich model was used for adsorption isotherms modelling. The Pearson correlation coefficient of the linearised Freundlich model achieved r = 0,98. The biosorption process has been described as a spontaneous endothermic process, where both chemisorption and physical adsorption are present. Therefore, the most suitable temperature for hexavalent chromium biosorption onto chemically activated citrus peels was chosen to be t = 40 °C.