B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
B01D—SEPARATION
B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
B01D53/34—Chemical or biological purification of waste gases
B01D53/46—Removing components of defined structure
B01D53/64—Heavy metals or compounds thereof, e.g. mercury