A method of sanitising seawater at a subsea location comprises: exposing flow of seawater in a treatment reactor to UV radiation that sanitises the seawater without the addition of sanitising chemicals; and outputting the sanitised seawater from the reactor into a subsea structure such as a pipeline or a wellhead. The flow of seawater may be exposed to successive emitters of UV radiation such as pressure-compensated LEDs. The efficacy of sanitisation may be determined by: injecting a tracer fluid into the flow of seawater upstream of the reactor; and, downstream of the reactor, sensing transformation of the tracer fluid due to exposure of the tracer fluid to the UV radiation in the reactor.

An ultraviolet irradiation device includes an inner cylinder forming a treatment flow path, an inflow portion allowing the object to flow into the treatment flow path, an outer cylinder accommodating the inner cylinder, a light emitting element irradiating the object passing through the treatment flow path with ultraviolet light, an O-ring dividing a space provided between an outer circumferential surface of the inner cylinder and an inner circumferential surface of the outer cylinder into a first chamber through which the object before ultraviolet irradiation passes and a third chamber through which the object after the ultraviolet irradiation passes, and a second chamber communicating with the first chamber through communication holes. The second chamber communicates with the treatment flow path through a plate.

Metal working fluid decontamination apparatus (10) includes: an intake arrangement (40) for metal working fluid (42); a pump (16) for providing, in use, flow pressure to the metal working fluid (42); a decontaminator (50) for reducing contamination in the metal working fluid (42); and an outlet arrangement (34) for the metal working fluid. The metal working fluid (42) is a fully synthetic metal working fluid, which comprises water and a water soluble synthetic concentrate which does not comprise oil.

A sanitizing apparatus for sanitizing a fluid is provided. The sanitizing apparatus includes a chamber having an inlet for receiving the fluid thereinto and an outlet for discharging the fluid therefrom, a divider adapted to divide the chamber into an upstream portion in fluid communication with the inlet and a downstream portion in fluid communication with the outlet, a sanitizing light source disposed in the upstream portion and adapted to emit a sanitizing light to sanitize the fluid therein, such that the divider is adapted to obstruct the fluid flow from the inlet to increase the density of the fluid in the upstream portion wherein the fluid is sanitized before being discharged from the chamber via the outlet. A sanitizing method for sanitizing a fluid is provided.

The invention relates to the detection, assessment and mitigation of harmful water-borne bacteria such as cyanobacteria. Multiple apparatus embodiments and variations are described. One apparatus can apply at least one of UV-C irradiation, microbubbles containing ozone and ultrasonic sound to mitigate the harmful water-borne bacteria. The systems and methods of the invention can be applied to bodies of water, including fresh water and salt water, and can be applied to wastewater treatment. The systems and methods of the invention can be used to reduce the concentration of algae directly and can be used to reduce the concentration of nutrients in water that algae use to grow. Methods of mitigation of the harmful bacteria are described that do not involve the introduction of chemicals into the environment.

The invention relates to the detection, assessment and mitigation of harmful water-borne bacteria such as cyanobacteria. Multiple apparatus embodiments and variations are described. One apparatus can apply at least one of UV-C irradiation, microbubbles containing ozone and ultrasonic sound to mitigate the harmful water-borne bacteria. The systems and methods of the invention can be applied to bodies of water, including fresh water and salt water, and can be applied to wastewater treatment. The systems and methods of the invention can be used to reduce the concentration of algae directly and can be used to reduce the concentration of nutrients in water that algae use to grow. Methods of mitigation of the harmful bacteria are described that do not involve the introduction of chemicals into the environment.

A flow-through fluid purification device (1), which comprises a container (5) arranged such that fluid to be purified can flow-through a volume (8) of the container (5) from an inlet (3) to an outlet (7), a receptacle (10) for accommodating a radiation source in the form of a lamp (13), wherein the receptacle (10) has an interface wall (11) permeable for radiation with a wavelength in the UV-range, preferably between 150 nm and 200 nm, more preferably of 172±8 nm, and arranged to let radiation pass into the volume (8) of the container (5), a plurality of baffle plates (9) located in the volume (8) of the container (5) with an inter-baffle distance (D) in the flow direction from the inlet (3) to the outlet (7), wherein the baffle plates (9) are arranged to force the fluid flowing from the inlet (3) to the outlet (7) to flow substantially along the interface wall (11) and through gaps (G) between the interface wall (11) and the baffle plates (9) defining the shortest distance between the interface wall (11) and the baffle plates (9), and wherein the baffle plates (9) each have a surface on the upstream side in the flow direction which is perpendicular to the interface wall (11).

An ultraviolet (UV) light disinfection system for treating water prior to its delivery to a water usage device. One or more UV light emitting diodes (LEDs) are positioned within a water system floor interface in order to expose water flowing through the system to germicidal light treatment.

A sterilization device includes: a processing chamber in which a fluid passing through a straightener flows in a first direction, the straightener being provided at an inlet of the processing chamber; a plurality of light emitting devices arranged in an array on a plane facing the straightener in the first direction, sandwiching the processing chamber, and irradiating the fluid in the processing chamber with ultraviolet light; a light source chamber that houses the plurality of light emitting devices inside; and a discharge path provided to the side of the light source chamber and allowing the fluid passing through the processing chamber to flow in the first direction.

An apparatus for the treatment of a liquid that includes a chamber having at least one inner surface, the chamber adapted for passage of a fluid therethrough. The chamber is at least 80 percent enclosed. The apparatus also includes an optional ultraviolet-transmissive tube disposed within the chamber and also adapted for the passage of the liquid therethrough. The apparatus further includes an ultraviolet lamp disposed within the chamber and, optionally, within the ultraviolet-transmissive tube. A reflective material is interposed between the chamber and the transmissive tube. The reflective material is adapted so as to reflect at least a portion of light emitted by the ultraviolet lamp, wherein the reflective material is at least 80 percent reflective.