EQUILIBRIUM AND KINETIC STUDIES OF IRON (II) REMOVAL FROM 34% CALCIUM CHLORIDE SOLUTIONS BY CHELATING RESIN PUROLITE S930

作者：Popa Camelia^*; Bulai Petru; Macoveanu Matei

来源：Studia Universitatis Babes-Bolyai Chemia, 2011, 56(1): 129-143.

• Iron (II) removal
• Purolite S 930
• Sorption isotherm
• Thermodynamics
• Kinetics

This work presents equilibrium, thermodynamic and kinetic studies of iron removal from 34% CaCl(2) solution (that was obtained from electrolysis sludges) using chelating resin Purolite S930 with iminodiacetic acid functional groups.
Batch sorption experiments were performed using both forms of the resin (S930-Na and S930-H) by varying the initial conditions such as initial solution pH (2.0-5.0), initial concentration of iron (20-400mg/L), solution temperature (22-40 degrees C) and contact time (10 minutes up to 24 hours). The practical capacity of the resin increases with initial solution pH, temperature and the initial concentration of iron(II). Freundlich constants (n) had values bigger than 1 for the whole range of temperature that was studied, so, the sorbtion of iron on Purolite S930-Na form resin is a favourable one. The values of correlation coefficients (R(2)) higher than 0,99 show that on the studied concentration (200-400mg Fe(II)/L) and temperature (295-313 K) range the data were more suitable to the LangmuirI model. The values obtained for the Langmuir (R(L)) constant (0 < R(L) < 1) show a favourable isotherme for the whole range of temperature that was studied (295-313 K). The maximum sorption capacity (q(max)) was 238 mg Fe(II)/g for pH5. The values of calculated thermodynamic parameters (Delta G(0), Delta H(0) and Delta S(0)) indicate that the sorption of iron onto Purolite S930 resin is an endothermic and spontaneous process. The kinetic data show that, initially, sorption increases rapidly, but after that, the rate becomes slower; the equilibrium can be considered attained after 24 hours. Kinetic studies reveal that the sorption of iron from 34% CaCl(2) solution onto chelating resin follows a pseudo-second order model.

• 出版日期2011