Improving the Removal Efficiency of Elemental Mercury by Pre-Existing Aerosol Particles in Double Dielectric Barrier Discharge Treatments

10.4209/aaqr.2014.12.0334

Qing Li；Jing-Kun Jiang；Lei Duan；Jian-Guo Deng；Lun Jiang；Zhen Li；Ji-Ming Hao

Mercury removal ； Aerosol particles ； Plasma ； DDBD ； Pollution control

Aerosol and Air Quality Research

15卷4期（2015 / 08 / 01）

1506 - 1513

英文

Plasma technology has been employed for the removal of gaseous elemental mercury (Hg^0) from simulated flue gases without pre-existing airborne particles. This study developed a double dielectric barrier discharge (DDBD) treatment system, in which two coaxial electrodes were covered by quartz dielectrics, for removing mercury with the presence of aerosol particles. The increase in pre-existing aerosol surface concentration can improve Hg^0 removal efficiency up to 160% in the DDBD device. Inorganic aerosol particles (sodium chloride) perform better than organic ones (sucrose) in improving Hg^0 removal efficiency. These aerosol particles can be collected in the DDBD system. For sodium chloride particles, a collection efficiency of more than 90% was observed in the tested diameter range of 10-100nm. The improvement in Hg^0 removal with the presence of particles is possibly due to that (i) aerosol particles provide additional surface for surface-induced Hg^0 oxidations, (ii) reactive species (such as Cl) generated by plasma etching particle surface rapidly react with Hg^0, and (iii) charged particles can in-flight adsorb mercury species.