Studium vlivu Cr(III) na stanovení Cr(VI) sorbovaného pomocí slupek ořešáku královského (Juglans regia)

Abstract

This thesis deals with the study of Cr(IV) adsorption kinetics depending on the method of physical and chemical treatment of walnut shells samples (Juglans regia). The thesis describes the methodology of particle size and heat treatment of biosorbent samples, including their chemical activation. Samples were chemically activated with 0,1 mol/l, 1 mol/l, 2 mol/l hydrochloric acid to activate cellular binding sites of walnut shells (Juglans regia). The effect of trivalent chromium on the determination of hexavalent chromium was verified by determination of the sorption capacity (equilibrium) and capture velocity (kinetics) of hexavalent chromium after the precipitation of trivalent chromium. Included is a comparision of the sorption capacity and capture velocity of hexavalent chromium without the precipitation of trivalent chromium. Samples with hexavalent chromium were analysed using spectrophotometry with 1,5-diphenylcarbazide. The greatest sorption efficiency, 2.48 mg/g, was achieved at the sorbent size fraction 3 - 4 mm and chemical activation with 2 mol/l hydrochloric acid for 30 min. In this case the sorbent efficiency was 49 %.