ADSORPTION OF PHOSPHATE IONS ON RED SLUDGE

In work the possibility of red sludge (waste of aluminum production by Bayer's method) to adsorb phosphate ions from water solutions at various concentration of ions and in the pH range from 3 to 10 is studied. Relevance of use of red sludge for receiving on its basis of sorbents is reasoned. For identification of the studied object the qualitative and quantitative composition of red sludge was established by the method of the X-ray phase analysis. The technique of red slage activation by hydrochloric acid, and also an adsorption technique of phosphate ions on the red sludge surface is described. Experimental studies of adsorption of phosphate ions on the surface of the red slage activated by hydrochloric acid depending on рН and concentration of initial solution were conducted. The dependence of adsorption phosphate ions on the red slage activated by НСl on рН and on the initial concentration of phosphate ions in solution is presented. These dependences of a relative fraction of distribution of various ions of phosphoric acid on рН are given in work. The form of ion phosphate having the greatest adsorptive activity on the red slage activated by hydrochloric acid in experimental conditions is revealed. Experimental data on dependence of adsorption of phosphate ions on their initial concentration in solution are described by Frumkin's isotherm. The constant of the adsorptive balance, limit adsorption, the parameter of intermolecular interaction of the adsorbed particles are calculated. Optimum conditions for adsorption of phosphate ions on red slage are established.Forcitation:Kramer S.M., Terekhova M.V., Artamonova I.V. Adsorption of phosphate ions on red sludge. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 8. P. 80-83.

Effect of Fe(III) on specific adsorption of aliphatic carbamide derivatives at the dropping mercury electrode

The specific adsorption of carbamide and its aliphatic derivatives (L) was studied by the droptime method in the system Fe(ClO4)3-L-HClO4-H2O, and the adsorption process was elucidated. From the calculated surface concentrations and adsorption isotherms, it was found that the adsorption of aliphatic carbamide derivatives is higher in the presence of Fe(III) ions than in their absence under the same conditions. In the presence of Fe(III) ions at the interface, free molecules of carbamide derivatives and the complexes [Fe(H2O)6-nLn]3+ as well as the complexes [Fe(H2O)5-nLnLads]3+ and [Fe(H2O)5-nLnLads]2+ formed with the adsorbed ligand are adsorbed. The adsorption was found to proceed according to the Frumkin's isotherm.