LV14846B - Method for water desinfection by ultraviolet radiation and device therefore - Google Patents

Abstract

Invention is related to water purification from organic and mineral substances and its disinfection by an ultraviolet radiation. The offered method is implemented by placing a source of ultraviolet radiation above the wall, which separates a polluted water volume from a pool of purified water, creating an overfall bar. The overfall bar, where the layer of water is accessible for ultraviolet radiation can be extended by widening or elongating of the separating wall. Disinfecting source of ultraviolet radiation is covered by a protecting shield, which can have a reflecting surface. The method allows to perform maximally effective UV-disinfection of water, as the layer of water, crossing the overfall bar, does not exceed the depth of penetration of ultraviolet radiation.

Description

Description of the Invention

The present invention relates to the purification of water from organic and mineral substances and its disinfection with ultraviolet radiation.

UV Disinfectant (Prior Art)

The supply of cheap, usable water has declined significantly over the last century. Water consumption is expected to increase due to population growth and environmental pollution. Throughout the world, industry and governments are spending ever greater effort to develop modern water purification plants that meet societal demands and set the strict standards needed to create a cleaner environment. The need for economical, environmentally friendly industrial waste water treatment is rapidly approaching a critical point. Ultraviolet water disinfection has significant advantages over known chlorinating or ozonation water disinfection methods.

The disinfectant effect of UV radiation is based on the irreversible damage of microorganisms' DNA and RNA molecules caused by changes or breaks in the chemical bonds of organic molecules, which are in turn determined by photochemical reactions that are stimulated by the energy of the absorbed rays. Ultraviolet light treatment of water, air and surface has no prolongation effect. The advantage of this feature is that harmful effects on humans and animals are eliminated.

Ultraviolet disinfection is carried out by irradiating microorganisms in the water with a certain intensity of UV radiation over a period of time (the wavelength of radiation is 260.5 nm sufficient for the complete destruction of microorganisms). As a result of this exposure, microorganisms die "microbiologically" because they lose their reproductive capacity. UV radiation in the wavelength range around 254 nm penetrates well into water and into the cell of the microorganism, which is carried by water, and is absorbed by the DNA of the microorganisms, causing damage to its structure. As a result, the growth of microorganisms is stopped. The environment for the detection of microorganisms is essential for the effectiveness of disinfection as it can absorb or shield UV radiation.

In general, UV or disinfection of air or surface requires several times less energy than disinfection in water. Physical and chemical properties of the environment primarily affect the economic performance of the process: the more transparent the environment is to ultraviolet rays, the less energy is required to provide the same dose. Secondly, the effectiveness of the disinfection process is determined by the presence of solids (suspended particles), which protect microorganisms from ultraviolet rays and reduce the effectiveness of disinfection.

The most basic low-power pressure-type equipment (with ultraviolet-submerged radiation sources) consists of a housing containing UV lamps enclosed in a protective quartz housing. Equipment with submerged ultraviolet radiation provides a higher efficiency in the use of bactericidal radiation, but is structurally more complicated and must not allow contamination of the protective quartz casing during operation.

Gutter type devices (with non-submersible UV radiation sources) are simpler in construction and operation, but use of bactericidal power is less effective because their depth of use is limited by the thickness of the water layer that is transparent to UV radiation. Placing such a device on top of a reservoir or water flow does not disinfect the entire volume of water as it only kills microorganisms in the upper water layer and is therefore used to disinfect only a very small amount of water.

The closest analogue to the present invention is a fish farming device as defined in patent LV 13066, which uses surface ultraviolet lamps to disinfect the water, located above one of the zig-zag biofilter channel thresholds, which allows water to be disinfected at the depth of the barrier. However, this arrangement does not guarantee that further micro-organisms do not enter the water to be treated, since the water stream then enters the next section of the biofilter and can interact with new micro-organisms.

Purpose and substance of the invention

The present invention solves the problem of reliability and completeness of water flow disinfection and provides low energy consumption of ultraviolet treated water, as well as increases the safety and maintenance of the disinfectant.

A distinctive feature of the proposed technique is the placement of an ultraviolet radiator directly above the wall, which separates the amount of contaminated water from the purified water reservoir, which forms a water barrier threshold where ultraviolet radiation reaches the water layer completely. The water barrier threshold in the reservoir for increasing the irradiance area and the ultraviolet radiation may be increased by extending or extending the partition wall. The ultraviolet emitter, which implements the technique, is positioned above the water barrier threshold in the very thinnest layer and is sealed with a shroud that delimits the ultrasonic exposure area and directs the ultraviolet radiation to the water stream flowing over the barrier threshold. To enhance the effect of ultraviolet radiation, the housing may be provided with a reflective surface.

The general scheme of the proposed ultraviolet water disinfection unit is shown in FIG. The ultraviolet radiator 1 is sealed with a sheath 2 and positioned above a wall 3 which divides the volume of contaminated water 4 from the purified water reservoir 5 and forms a water barrier threshold 6.

For carrying out the proposed method of disinfecting water by means of an ultraviolet radiator, the ultraviolet radiator is placed over a wall 3 which divides the volume of contaminated water 4 from the purified water reservoir 5 and forms a barrier threshold 6. Water flowing over the barrier threshold is completely accessible to ultraviolet radiation. The ultraviolet radiator shroud 2 delimits the radiation exposure area and directs the ultraviolet radiation directly to the water layer above the barrier threshold. The housing may be provided with a reflective surface.

The water barrier threshold can be increased by extending the partition wall to increase the exposure time to ultraviolet radiation, while the barrier threshold can be increased by extending the partition wall to increase the volume of water to be disinfected.

The present invention enables ultraviolet water disinfection with maximum disinfectant effect, since the thickness of the water layer flowing over the threshold does not exceed the penetration depth of the ultraviolet radiation. The ultraviolet seal enclosure guides and delimits the ultraviolet zone, which ensures the safety of the unit and at the same time enhances its direct function. In addition, the surface of the reflective surface increases the area and intensity of the water to be treated with ultraviolet radiation.

Extending the barrier threshold can increase the flow of disinfected water, but extending the barrier threshold by increasing the area of exposure to ultraviolet radiation provides additional safety to the disinfectant flow. The offered equipment ensures maximum water disinfection with maximum energy consumption. The equipment is cheap to manufacture and safe to use.

Claims (5)

1. A method of disinfecting water by means of ultraviolet radiation, the water flowing over the barrier threshold, characterized in that the ultraviolet radiator which disinfects is placed directly above the wall which separates the volume of contaminated water from the purified water reservoir and forms the barrier to the water ultraviolet radiation reaches the water layer completely. A method according to claim 1, characterized in that, in order to increase the time of exposure to ultraviolet radiation, the threshold of the water barrier at which ultraviolet radiation reaches the water layer completely is expanded by expanding the partition wall. Method according to claim 1, characterized in that the barrier threshold is increased by extending the partition wall to increase the volume of disinfecting water. Apparatus for implementing the method according to any one of claims 1 to 3, comprising a gutter-type ultraviolet radiator, characterized in that the ultraviolet radiator is covered on its face by a shroud which delimits the ultraviolet radiation region and directs the ultraviolet radiation to water. flow over the barrier threshold. Apparatus according to claim 4, characterized in that the ultraviolet radiation-sheathing is formed by a reflective surface.