Removal and recovery of gas-phase element mercury by metal oxide-loaded activated carbon.

The reusability of Co(3)O(4) (AC-Co), MnO(2) (AC-Mn) and CuCoO(4) (AC-CC) loaded activated carbon (AC) and their element mercury removal efficiency had been studied using a laboratory-scale fixed-bed reactor under simulated flue gas conditions. Tests showed that spent AC-Co could be regenerated through heating at 673 K under N(2) atmosphere and the enrichment regenerated Hg(0) could be collected to eliminate the secondary pollution. Regenerated AC-Mn and AC-CC's Hg(0) removal efficiency decreased greatly due to AC's decomposition and MnO(2)'s crystal structure variation. Compared with AC and metal oxides, metal oxide-loaded AC had higher Hg(0) capture ability and capacity due to AC huge surface areas and lots of function groups. TGA analysis results showed that AC-Co and AC-Mn's HgO adsorptive capacity at 523 K reached 19.8 mg g(-1) and 5.21 mg g(-1), respectively. High loading values and adsorption temperatures were beneficial to AC-Co's Hg(0) removal efficiency. However, CuCoO(4) and MnO(2)'s AC decomposition ability had negative effect on AC-CC and AC-Mn's performance, respectively, especially at high adsorption temperatures and loading values. SO(2) tests showed that AC-CC had higher anti SO(2)-poisoning ability than AC-Co and AC-Mn.