Effect of Temperature on the Kinetics of Sorption of Co2+ and Ni2+ Ions by a Sorbent Based on an Inositol Hexaphosphoric Acid Derivative

Resumo

Data on the effect temperature has on the kinetics of the removal of Co²⁺ and Ni²⁺ ions under static conditions by a sorbent based on a derivative of phytic acid fabricated from rice production waste are presented. It is shown that when the temperature is raised from 20 to 60°C, the sorption capacity of the sorbent based on phytic acid increases over the period of sorption and within 180 min reaches values of 1.4 mmol g⁻¹ for Co²⁺ ions and 1.3 mmol g⁻¹ for Ni²⁺ ions. It is established that for the investigated range of temperatures, order n of the sorption of Co²⁺ and Ni²⁺ ions is <1, which characterizes the reactions accompanied by diffusion processes. It is found that the process of removal of Co²⁺ and Ni²⁺ ions is characterized with low activation energy (20.74 kJ mol⁻¹ for Co²⁺ ions and 14.2 kJ mol⁻¹ for Ni²⁺ ions). It is also demonstrated that the sorption process in the considered time frame is best described by a kinetic model of a pseudo-second order, as is indicated by respective correlation coefficients.