A water filter system includes an upper chamber removably coupled with a lower chamber. In implementations the lower chamber has a sidewall and a rim wider than the sidewall. A filter medium filters water from the upper to the lower chamber. A seal couples between the chambers and has a circular cross-section and a gap receiving a portion of the sidewall. The seal may also have a cavity receiving the rim. The seal includes one or more arced flaps contacting the upper chamber, a tip of each arced flap defining a circular inner opening of the seal. The seal includes one or more first barbs contacting the upper chamber, each first barb forming a circle. The seal includes one or more second barbs contacting the lower chamber, each second barb forming a circle.

A system disinfects air. The system includes an elongated chamber having an inlet configured for air to flow into the chamber. The chamber also has an outlet configured for air to flow out of the chamber, and a sidewall formed from a material that is at least 90% UVC reflective. The chamber defines a longitudinal axis. A LED is positioned to emit UVC radiation in a direction substantially perpendicular to the longitudinal axis of the chamber. A filter is configured to trap pathogens. The filter is formed of a material that is UVC reflective and UVC transmissive.

The invention provides a solution for biofouling in HVAC condensate drain systems, including drain pans and drain lines, using ultraviolet (UV) radiation. Embodiments of the invention include one or more of: one or more ultraviolet (UV) radiation sources, positioning mechanisms for the UV radiation sources, and one or more UV radiation source control systems. Specific location of the UV radiation source control system(s) can be proximal to the UV radiation sources, or located remotely.

In various embodiments, a fluid is treated by flowing the fluid through a flow cell having (i) a fluid entry, (ii) a fluid exit, (iii) a treatment region disposed between the fluid entry and exit, and (iv) an interior surface reflective to ultraviolet (UV) light, and diffusively reflecting UV light emitted from one or more UV light sources to illuminate the treatment region substantially uniformly, thereby treating the fluid.

A fluid treatment device includes a pipe including an inlet, an outlet, an internal space through which a fluid moves and including a light source part disposed in the internal space and providing a light to the fluid. The light source part includes at least one light source unit having a substrate and a plurality of light sources disposed on the substrate and emitting the light. A ratio of a first distance between two light sources adjacent to each other to a second distance between each light source and an inner circumferential surface of the pipe is 1:1.25 or less when viewed in a longitudinal-section.

Various ultraviolet (UV) reactors and their methods of fabrication are disclosed. One exemplary process comprises forming a set of parallel channels in a slab of ultraviolet transparent material. The process also comprises providing a reactor substrate with an input manifold and an output manifold. The process also comprises joining the slab of ultraviolet transparent material and the reactor substrate. The input manifold, output manifold, and set of parallel channels are in fluid communication after the joining step. The process also comprises providing a planar ultraviolet light source isolated from the set of parallel channels by the shaped slab of ultraviolet-transparent material. The set of parallel channels and a defining plane of the planar ultraviolet light source are parallel in the assembled ultraviolet reactor.

An internal ultraviolet-C light emitting diode antifouling system and method that include a waterproof, light transmissible potted enclosure; an object disposed within the waterproof, light transmissible potted enclosure; and at least one ultraviolet-C light emitting diode disposed within the waterproof, light transmissible enclosure, wherein the at least one ultraviolet-C light emitting diode is configured to emit light on the object, wherein the light is configured to prevent biofouling on the object.

A self-cleaning fountain includes: a structure having two ends, defining a first flow way for a first fluid to flow along, wherein the structure defines holes for allowing a second fluid to flow through the holes; a pump system configured to pump the first fluid to a first end of the structure; a distributer located at the first end of the structure and configured to spray the first fluid received from the pump system onto the structure; a catch basin located at a second end of the structure for collecting the first fluid that has moved along the flow way to the catch basin; a photocatalytic coating on the structure; and a light source configured to direct light on the photocatalytic coating.

A method of removing at least one single ring aromatic hydrocarbon from a hydrocarbon contaminated fluid. The method includes contacting the hydrocarbon contaminated fluid with carbon nanotubes to adsorb the at least one single ring aromatic hydrocarbon while exposing the hydrocarbon contaminated fluid and the carbon nanotubes to UV irradiation from at least one UV light source, preferably a UV light emitting diode (LED), with a wavelength of about 315-415 nm, preferably about 365 nm, to form a treated fluid having a reduced concentration of the at least one single ring aromatic hydrocarbon relative to the hydrocarbon contaminated fluid.

This invention is directed to a method, system and apparatus for the treatment fluids. An apparatus for the treatment of a fluid comprises a fluid chamber and at least one ultraviolet light unit arranged at a periphery of the fluid chamber. The at least one ultraviolet light unit comprises at least one ultraviolet light emitting diode and an ultraviolet light directing element. The ultraviolet light directing element is configured to collimate at least a portion of the light emitted from the at least one ultraviolet light emitting diode in use such that the ultraviolet light rays emitted from each ultraviolet light unit are parallel in a first plane. Also described is a method for the cooling a light emitting diode in a fluid treatment system.