Abstract: In this study, we investigated the mechanism of action of calcium sulphite in the clarification of sugar cane juice on the basis of the morphology and structure of calcium sulphite particles. The results revealed that the surface of calcium sulphite particles showed a porous and loose structure, leading to better removal of colloidal particles suspended in sugar cane juice. The kinetic data were described better by the pseudo-second-order kinetic model. The adsorption isotherm was fitted with the Temkin model and thermodynamic parameters suggested that the adsorption process was a spontaneous and endothermic process. Furthermore, the calcium sulphite particles were thoroughly characterized by X-ray diffraction and Fourier transform infrared spectroscopy in order to further understand the mechanism of calcium sulphite adsorption and trapping in sugar juice clarification.

Key words: calcium sulphite, sugar juice clarification, morphology and structure, mechanism