Abstract: An air treatment device for removing unwanted substances from air, the air treatment device comprising: a non-thermal plasma reactor stage housing comprising an air inlet for receiving the air to be treated, a plurality of non-thermal plasma reactor units for treating the air and an air outlet for exhausting the treated air from the non-thermal plasma reactor stage housing; wherein each of the plurality of non-thermal plasma reactor units comprises a dielectric substrate having a first surface and a second surface, a first electrode disposed on the first surface of the dielectric substrate and a second electrode disposed on the second surface of the dielectric substrate, wherein the first electrode comprises at least one window exposing the dielectric substrate to the air to be treated in the non-thermal plasma reactor stage housing.

Abstract: Apparatus comprising: a fumehood; and an air treatment device for purging unwanted substances from the exhaust air of the fumehood, the air treatment device comprising: a non-thermal plasma reactor stage for producing air byproducts comprising O., N., OH. and O3 and introducing those air byproducts into the exhaust air of the fumehood so as to treat the exhaust air of the fumehood; and a catalyst stage downstream of the non-thermal plasma reactor stage for further treating the air downstream of the non-thermal plasma reactor stage.