Using novel gold nanoparticles-deposited activated carbon fiber cloth for continuous gaseous mercury recovery by electrothermal swing system

Novel gold nanoparticles (AuNPs) deposited activated carbon fiber cloth (ACFC) was successfully developed in this study. This material showed great potential in combining with an electrothermal swing (ETS) system to sustainably adsorb and recover low-concentration elemental mercury (Hg-0) in gas stream. ACFC with Au loading ratio of 0.5 wt% (0.5 wt%-ACFC-THPC) demonstrated the largest Hg-0 adsorption capacity. Hg temperature programmed desorption results suggested that Hg0 was physically adsorbed by AuNPs on Au-ACFC-THPC via amalgamation, while it was both physically and chemically adsorbed by pore structures or carbonyl groups on Raw-ACFC. The Hg-0 adsorption efficiency of 0.5 wt%-ACFC-THPC was approximately 95% and remained stable during the cyclic ETS operation under various Hg0 inlet concentrations (30, 75, and 100 mu g m(-3)); however, the adsorption efficiency of Raw-ACFC greatly decreased to 65-75% as Hg0 inlet concentration increased to 75 and 100 mu g m(-3). Furthermore, the regeneration efficiencies of all ACFCs were > 90% within 6 min; indicating the promising application in concentrating Hg-0 vapor and the subsequent recovery process. Mass transfer models for the simulation of Hg-0 desorption within ACFCs were further conducted; the simulation results suggested that intraparticle diffusion dominated the desorption process for both Raw-ACFC and 0.5 wt%-ACFC-THPC.

Automated summary

This study successfully developed a novel gold nanoparticle-impregnated activated carbon fiber cloth material, which has the potential to adsorb and recover low-concentration elemental mercury. The gold nanoparticles physically adsorb mercury through amalgamation, while the activated carbon fiber cloth adsorbs it through pore structures or chemical adsorption. The material shows good stability and high adsorption efficiency during cyclic operation.