A mask with at least one filtering layer that includes a fabric made of non-conductive polymer fibers embedded with nanoparticles of two different metals is provided. The population density of the nanoparticles of the two metals on the surface of non-conductive polymer fibers is configured such that the adjacent nanoparticles of the two metals have an average distance of two micrometers or less. The two different metals are selected such that the electric field intensity generated between the nanoparticles of the two different metal through the aerosol particle inactivates the microorganisms that may be inside the aerosol particle. When an aerosol particle comes into contact with the nanoparticles of the two metals, the aerosol acts as an electrolyte between the two metal types and a potential difference and an electric field is generated, through the aerosol particle, between the nanoparticles of the two metals.

Metal nanoparticle agglomerates may convey biocidal activity to surfaces upon which they are deposited and become adhered, such as various air filtration media. Air filtration media may comprise a plurality of fibers having a plurality of metal nanoparticle agglomerates adhered thereto. The metal nanoparticle agglomerates may comprise a plurality of fused, partially fused, or unfused metal nanoparticles that are associated with one another upon a surface of the plurality of the fibers. Suitable metal nanoparticles for promoting biocidal activity against various pathogens, such as viruses and bacteria, may include copper nanoparticles and/or silver nanoparticles. Masks, inline filters, and air filtration systems may incorporate the air filtration media.

A combination of nanoparticles applied onto a mask filtration system, exemplarily including 1%-10% graphene; 1%-10% titanium dioxide; 1%-10% zinc oxide; 1%-10% copper oxide; 1%-10% silicon dioxide; and balance solvent is provided.

Proposed is a multi-layer filtration system including a metal catalyst filter unit, a carbon filter unit, and an inorganic compound filter unit. The metal catalyst filter unit includes at least one among metals including Ni, Co, Fe, Cu, Cr, Mg, Zn, Ba, Au, Ag, Pd, Pt, Ru, Mn, and Ti, oxides thereof, and mixtures thereof. The carbon filter unit includes at least one of activated carbon or activated carbon fiber. The inorganic compound filter unit includes an inorganic compound capable of adsorbing toxic gas. The multi-layer filtration system has good removal effect for toxic gas. A filter module including the multi-layer filtration system and a gas mask including the multi-layer filtration system are also proposed.

Provided are anti-pathogenic sintered nanoparticle compounds made of zeolite, silver nitrate (AgNO.sub.3), silver dioxide nanoparticles (Ag.sub.2O np), and graphene. Provided are enhanced granulated activated charcoal (EGAC) compounds made of granulated activated charcoal, silver nitrate (AgNO.sub.3), silver dioxide nanoparticles (Ag.sub.2O np), and graphene. Uses of the same are provided, including in enhanced filtration systems and/or pressurized wastewater filtration plants.

A filter medium for removal of contaminants from wastewater. The filter medium includes a walnut shell particle having a metal hydro(oxide) nanoparticle bonded to the surface of the nut shell particle. The filter medium is particularly useful for treating produced water and wastewater generated in steam-assisted gravity drainage (SAGD) in recovery of hydrocarbons from oil sands to remove total organic carbon and silica. Processes for preparing the filter medium and for treating wastewater using the filter medium are also provided.

An antimicrobial air treatment device and a method of its construction. The antimicrobial air treatment device comprises an antimicrobial metal nanoparticle mesh comprising a steel support mesh and a layer of copper nanoparticles disposed on the steel support mesh. The antimicrobial air treatment device may be in the form of a facemask or a component of a moving air filtration system such as an HVAC system, an automobile cabin air filtration system, and an air purifier. The antimicrobial air treatment device may contain one or more filtration layers of filtration medium. The method of constructing the antimicrobial air treatment device involves the preparation of the antimicrobial metal nanoparticle mesh by an electrodeposition technique.

An exhaust treatment apparatus for treating exhaust gas flowing through an exhaust line housing from an upstream location to a downstream location in a downstream direction, the exhaust treatment apparatus comprising a ceramic filter body having a honeycomb structure of a plurality of intersecting porous ceramic walls extending from a first end to a second end in an axial direction and defining a plurality of channels extending in the axial direction, wherein a first transverse face at the first end comprises metal oxide particles affixed to a portion of the intersecting walls. The metal oxide particles may be affixed to the upstream end, or the downstream end, or both the upstream and downstream ends. Preferably the metal oxide particles provide reinforcement to the underlying portion of the walls, and of the honeycomb structure itself.

A layer for a protective mask (100a, 100b, 200a) comprises at least a first sublayer (122b, 218b), wherein the first sublayer (122b, 218b) includes a first substrate and a layer of a plurality of nanoparticles (124b, 7) of a nanomaterial provided on the first substrate. The protective mask (100a, 100b, 200a) includes an outer layer (120b, 230a) which is made of an organic fibular network bonded with nanomaterials. An air filtration element (900, 1070, 1240) for attenuation of airborne contaminants includes negatively charged nanodiamonds (920, 1320). A filter (1100, 1200, 1500, 1600) for an air conditioning system (1130, 1530) or an air purifier (1230, 1630) comprises the air filtration element (900, 1070, 1240). An air treatment element (1140,1300,1540,1640) comprises nanodiamonds (920,1320) including colour centers. The protective mask (100a, 100b, 200a), the air filtration element (900, 1070, 1240), the air treatment element (1140,1300,1540,1640) and the filter (1100, 1200, 1500, 1600) overcome or at least partially ameliorate some of the deficiencies as associated with those of the prior art.

The present invention provides a filter material comprising an antistatic substrate having a predefined antistatic capacity, and one or more layers of nanofibers applied on the substrate. The one or more layers of nanofibers may be fabricated to have gradient structure in various parameters including thickness of nanofiber layer, nanofiber pore size, nanofiber diameter, nanofiber content and the like to suit different filtration applications. The present invention also provides a face mask comprising the filter material and a method for making the filter material.