Removal of Hg 0 with sodium chlorite solution and mass transfer reaction kinetics

The absorption behavior of Hg 0 was studied experimentally by using sodium chlorite solution (NaClO 2 ) as the absorbent in a bubble reactor. Primary influencing factors on removal efficiency of Hg 0 such as NaClO 2 concentration, pH, reaction temperature and the concentration of Hg 0 were investigated. The results indicated that 72.91% of Hg 0 removal efficiency could be achieved in acidic NaClO 2 solution. The removal mechanism of Hg 0 was proposed by analyzing of Hg 2+ concentration in absorption solution after reaction and comparing the electrode potentials between NaClO 2 species and Hg 2+ /Hg 0 . The experimental results of mass transfer-reaction kinetics on oxidation of Hg 0 by NaClO 2 solution showed that with the increase of NaClO 2 concentration and the decrease of pH value, the enhancement factor ( E ) and ratio of K G (Hg 0 )/ k G (Hg 0 ) increased and the liquid phase mass transfer resistance decreased, which is benefit to the mass transfer adsorption reaction. Although the increase of reaction temperature could improve the enhancement factor ( E ), but the ratio of K G (Hg 0 )/ k G (Hg 0 ) decreased; as a result, the liquid phase mass transfer resistance increased, therefore, the reaction rate for removal of Hg 0 decreased.