An air purification system that includes a housing including a pedestal and an outer shell, wherein the outer shell is operable between an extended configuration and a compacted configuration, and includes a filter arranged within the housing along a flow path between an inlet and an outlet of the housing.

A filter includes a filter medium having an average pore size of 1 to 5 min, and photocatalyst particles deposited on the filter medium. The photocatalyst particle contains a titanium compound particle and a metal compound bonded to the surface of the titanium compound particle with an oxygen atom. The metal compound contains a metal atom and a hydrocarbon group. The titanium compound particle has absorption at wavelengths of 450 nm and 750 nm in the visible absorption spectrum of the titanium compound particle.

A photocatalyst material (1A) in accordance with an aspect of the present invention includes a core particle (2) and a shell layer (3) with which a whole surface of the core particle (2) is covered. The core particle (2) contains at least a tungsten oxide, and the shell layer (3) is constituted by a titanium oxide.

A fluid filtration system that includes one or more layers, including a trapping layer and a reactive layer, connected to a frame. A method for fluid filtration that includes sorbing contaminants, trapping contaminants, and degrading contaminants.

The present invention achieves a moisture absorbing material which enables efficient dehumidification without supercooling or large heat quantity; and a dehumidifier in which the moisture absorbing material is used. The moisture absorbing material can be a dried product of a polymer gel in which an interpenetrating polymer network structure or a semi-interpenetrating polymer network structure is formed by (a) a stimuli-responsive polymer whose affinity with water changes reversibly in response to an external stimulus and (b) a hydrophilic polymer.

The present invention provides a joint method of cultivating microalgae combined with denitrating an industrial waste gas and a system useful for the same. The joint method comprises the steps of: (1) a step of cultivating microalgae; (2) a separation step of separating a microalgae suspension obtained from step (1) into a wet microalgae (microalgae biomass) and a residual cultivation solution; (3) a NOx absorbing/immobilizing step of denitrating an industrial waste gas with the residual cultivation solution obtained from step (2); wherein the nutrient stream absorbed with NOx obtained from step (3) is used to provide nitrogen source to the microalgae cultivation of step (1). During the microalgae cultivation, EM bacteria is added into the microalgae suspension. The microalgae is preferably Chlorella sp., Scenedesmus sp., Monoraphidium sp. or Spirulina sp.

Disclosed is a visible light-activated photocatalytic coating composition comprising a visible light active photocatalytic material and an aqueous solvent.

A photocatalyst including a first metal oxide; and a second metal oxide, wherein the first metal oxide is disposed on a surface of the second metal oxide, and wherein absorbance of the photocatalyst in a wavelength region of about 200 nanometers (nm) to about 600 nm is about 5% to about 50% greater than an absorbance of TiO.sub.2 in the wavelength region of about 200 nm to about 600 nm.

Disclosed herein are methods of producing photocatalysts for degrading NOx. According to some embodiments of the present disclosure, the method comprises mixing a transitional metal or its oxide with a bone powder or a shell powder, followed by heating the mixture for a least 12 hours to dehydrate the mixture, and calcinating the dehydrated product for 1-5 hours. Also disclosed herein are methods of degrading NOx by using the thus-produced photocatalysts. Materials used doped with the transitional metal or its oxide are bone powder and shell powder, which is derived from animals (a chicken, a cow, a pig, a duck, a sheep, a donkey, or a horse) and shells from different species of sea water (a shrimp, a crab, a clam, a barnacle, a snail, an abalone, or an oyster), respectively.

The present invention relates to the field of air purification of indoor and/or domestic environments and has as its object a method for air purification and simultaneous photo-conversion of carbon dioxide to oxygen by exploiting a photosynthesis process of an algal culture comprised within an aqueous medium. The method according to the present invention therefore allows to purify the air of an indoor environment by abatement/solubilization of pollutants in the aqueous medium and reduction of CO.sub.2 contraction by photo-conversion into O.sub.2. The method according to the present invention further comprises the steps of illuminating and aerating said aqueous medium as well as a step of periodically maintaining said algal culture in a state of constant growth in order to optimize the photosynthesis of the algal culture.