Industrial & Engineering Chemistry Research, Vol.56, No.1, 153-160, 2017
In Situ Emergency Disposal of Liquid Mercury Leakage by Fe-Containing Sphalerite: Performance and Reaction Mechanism
The indoor concentration of mercury is often higher than the, reference concentration due to the historic accidents with mercury-containing devices. Therefore, there is a great demand to develop a treatment for the accidental breakage of the devices containing liquid mercury. In this work, Fe-containing sphalerite was developed as a cost-effective sorbent for the in situ emergency disposal of liquid mercury leakage, Fe-containing sphalerite showed an excellent performance for elemental mercury capture,at room temperature, with the capacity of much greater than 8.65 mg g(-1) and the reaction rate of 4.82 mu g g(-1) min(-1). The formed Hg species, on Fe-containing. sphalerite was HgS, so it was thermally stable at room temperature, poor leachable and low toxicity to microorganism. The chemical adsorption of elemental mercury on Fe-containing sphalerite mainly followed the Mars-Maessen mechanism and approximately followed a pseudo-zero-order kinetic reaction. The reaction rate of elemental mercury with Fe-containing sphalerite mainly depended on the concentration of Hg-0 physically adsorbed on the surface. The physical adsorption of Hg-0 on sphalerite was remarkably promoted after the incorporation of Fe, which may be mainly related to the presence of cation vacancies on Fe containing sphalerite.