Open AccessInvestigation of Thermodynamics of Adsorption of Cadmium Ions Cd (II) from Model Solutions by Glass Fiber Materials
Author(s) -
I V Letenkova
Publication year - 2021
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.179
H-Index - 26
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/852/1/012059
Subject(s) - gibbs free energy , adsorption , enthalpy , freundlich equation , thermodynamics , langmuir , chemistry , exothermic reaction , langmuir adsorption model , ion , cadmium , materials science , inorganic chemistry , organic chemistry , physics
Thermodynamic regularities of the adsorption of cadmium ions Cd (II) using BSTV basalt fiber and M20-STV-2.0 and M20-UTV-0.6 glass fibers are investigated. The adsorption capacity of the investigated fibers with respect to the cadmium ion Cd (II) was determined. The degree of adsorption, values of the distribution coefficient, and adsorption equilibrium constants for the Langmuir and Freundlich models were determined. The adsorption equilibrium for the cadmium ion Cd (II) is well described by the Langmuir model. Thermodynamic characteristics of the process were determined: the change in the Gibbs energy, the change in the enthalpy and entropy of the adsorption process at three temperatures. The change in the Gibbs energy corresponds to the spontaneous occurrence of the adsorption process. A decrease in the change in the Gibbs energy of adsorption in a series of fibrous materials (BSBV basalt fiber–M20-STV-2.0 glass fiber–M20-UTV-0.6 glass fiber) is due to the entropy effect. The adsorption of cadmium ions Cd (II) on glass fiber materials is exothermic. The values of the thermal effects, found by the graphical method in accordance with the isobar equation of the chemical reaction, do not exceed 25 kJ / mol and indicate the physical nature of the process.