This invention is a novel method to thermally process wet WWTP sludges, including biosolids, so that they can be classified. Wet biosolids or other WWTP sludges are passed through the heating zones of one or more solar thermal systems so that the sludges are heated to a target temperature to meet the requirements for U.S. Environmental Protection Agency classification. Various catalysts are provided before the sludges enter the heating zone and within the heating zone to optimize the treatment of the sludges.

An apparatus for treating a fluid comprises a fluid container having a chamber for holding the fluid and an ultraviolet (UV) reactor. The UV reactor comprises: an inlet in fluid communication with the chamber; an outlet located above the inlet; a conduit extending longitudinally between the inlet and the outlet to facilitate fluid flow from the inlet to the outlet in a first direction having a component antiparallel to the direction of gravity; and a UV emitter optically oriented to emit UV radiation directed toward the fluid travelling through the conduit. At least part of the chamber is located above the outlet to cause the fluid to flow from the chamber to the inlet and through the conduit to the outlet due to force of gravity.

Ultraviolet irradiation of liquids for purposes of sterilization, disinfection, cleaning and/or treatment. A liquid collection reservoir can receive an inflow of a liquid. A filtering unit can filter the inflow of liquid received by the liquid collection reservoir. A liquid chamber stores the liquid. Ultraviolet light emitting sources located about the liquid chamber irradiate the liquid in the liquid chamber with ultraviolet light. A control unit, operatively coupled to the ultraviolet light emitting sources, controls the irradiation of the liquid in the liquid chamber with the ultraviolet light emitting sources. The control unit is configured to control an intensity and a duration of the irradiation as a function of time that the liquid is stored in the liquid chamber and the amount of the liquid that is in the liquid chamber.

An optical arrangement for disinfection in apparatuses operating with air or a liquid comprises at least one radiation source or at least one group of radiation sources, which emits or jointly emit radiation in the ultraviolet wavelength range, at least one beam collecting optical unit, which collects the radiation emitted by the radiation source or the group of radiation sources, a number of beam delivering optical units, each configured to receive the radiation collected by the at least one beam collecting optical unit, and also a number of effect zones spatially separated from one another, into which the radiation delivered via the beam delivering optical units is emitted in order to bring about a disinfecting effect.

An ultraviolet sterilization device includes a liquid passing pipe assembly and an ultraviolet light source. The liquid passing pipe assembly includes a shell and a transparent hollow pipe, the shell is sleeved on the hollow pipe, the shell is provided with an accommodating groove. The ultraviolet light source is provided in the accommodating groove. An end of the hollow pipe is configured as a liquid inlet end, and another end thereof is configured as a liquid outlet end, and the hollow pipe is used for circulating liquid. The wall surface of the hollow pipe is covered with a reflective film, the reflective film is provided with first light transmitting holes at the position corresponding to the ultraviolet light source. The first light transmitting hole is communicated with the accommodating groove, and the reflective film is used for scattering the ultraviolet light in different areas in the hollow pipe.

A sterilizing device includes a pipe having an inlet and an outlet and allowing fluid to move therethrough and a light source provided on one side of the pipe and providing light to the fluid. At least a portion of the pipe is provided in a spiral shape and the inlet and/or the outlet are arranged in a light emitting region.

An apparatus and method for irradiating a fluid containing a material to be irradiated, comprising at least one irradiation chamber having at least one inlet port, one or more UV radiation sources inside the irradiation chamber(s) optically coupled to the fluid in the irradiation chamber(s) via at least one UV-transparent window in contact with the fluid; one or more seals or gaskets disposed adjacent to the radiation sources to protect them from the fluid; and at least one heat exchange mechanism inside the irradiation chamber(s) thermally coupled to the radiation sources and to the fluid. The UV radiation sources and the at least one heat exchange mechanism are at least partially submerged in the fluid in the irradiation chamber.

A method of monitoring light output from at least one solid-state light source involves sensing any light produced by the at least one solid-state light source and reflected, by at least one surface spaced apart from the at least one solid-state light source, to at least one reference location spaced apart from the at least one surface. Apparatuses and uses of the apparatuses are also disclosed.

An apparatus and method for irradiating a fluid containing a material to be irradiated, comprising at least one irradiation chamber having at least one inlet port and outlet port, at least one fluid cooling chamber having at least one inlet port and outlet port, one or more UV radiation sources coupled to the irradiation chamber(s); and at least one heat exchange mechanism thermally coupled to the radiation source(s) and the cooling chamber(s). At least a portion of the interior surface of the cooling chamber(s) may comprise at least a portion of the exterior surface of the irradiation chamber(s) so the cooling chamber(s) is in fluid communication with the irradiation chamber(s).

Described are light generating devices employing ultraviolet (UV) light emitting diodes and one or more UV active materials, such as UV reflective materials, UV scattering materials, and UV transparent materials. A UV light generation system, may include a plurality of UV light emitting diodes arranged across a surface having a diffuse UV reflective layer. The UV light generation system may be arranged to enclose a fluid pathway or may be arranged as a liner of a container or vessel for use in disinfecting, purifying, or sterilizing fluid, particles or objects in the fluid pathway, container, or vessel by exposure of the fluid, particles or objects to UV light generated by the UV light emitting diodes.