RU2114790C1 - Method and plant for producing super-pure drinking water - Google Patents

Abstract

FIELD: water treatment. SUBSTANCE: invention concerns ozonation- oxidation treatment of water. Prior to be involved into ozone synthesis, air is preliminarily cooled and dried and then pulverized and passed through layer of water. Undissolved ozone is decomposed by heating and subsequent passage through catalyst. Filtration is performed in three steps followed by demineralizing water. Plant includes air-preparation system consisting of compressor, drying unit, excess ozone-treatment system with heating device and catalyst; and filtration system consisting of in-series connected mechanical, sorption, and membrane filters wherein sorption filters have multilayer structure and filled by sorbents with different structures and densities. EFFECT: increased water detoxification degree. 2 cl, 1 dwg , 1 tbl

Description

 The invention relates to the treatment of water by oxidation using ozonation.

 A large number of methods and devices are known from the patent literature for producing pure drinking water by the ozonation method, for example [1], containing an ozone generator, a device for supplying water through a filter, a device for injecting ozone into water [2] "Method and installation for purifying circulating filtered water ", in which part of the water from the circulating system is removed, mixed with ozone, the process of decomposition by ozone of contaminants is carried out, passed through an activated carbon filter," Device and method for treating water with ozonation "[3], closed This is due to the fact that the water circulating in the pipeline forms a closed loop into which ozone is introduced.

 All existing methods and devices purify water using the ozonation method. It is universal because acts simultaneously in bacteriological, physical and organic terms. But they all have one significant drawback: a deviation from the standards for pure drinking water, significant fluctuations in the levels of pollution and the composition of impurities.

 These disadvantages are partially eliminated in [4], which is the closest to the proposed method. The known method is based on the use of ozone and is characterized in that the water, previously purified, is subjected to: a) ozonation at a concentration of ozone at which only oxidation occurs; b) mechanical filtration; c) biological oxidation using activated carbon containing microorganisms.

 Closest to the proposed installation is a device for processing ozone [5], containing an ozone generator, a reactor tank with a baffle, a unit for supplying treated water, a system for processing excess ozone, a filtration and control system.

 The purpose of the invention is the provision of a high degree of purification of drinking water under conditions of increasing load on surface and underground water sources in relation to super-ecotoxicants and other anthropogenic pollutants of a chemical and biological nature.

 This goal is achieved by the fact that in the proposed method for producing ultrapure drinking water, based on the use of ozone with subsequent mechanical filtration, the air is pre-cooled and dried before ozone synthesis, and then sprayed and passed through a layer of water, insoluble ozone is decomposed by heating and subsequent passage through the catalyst, and filtration takes place in three stages, after which the water is demineralized.

 In addition, the goal in the proposed installation for ultrapure water containing an ozone generator, a reactor tank with a longitudinal partition, a treated water supply unit, an excess ozone treatment system, a filtration and control system, is achieved by the fact that it is equipped with a synthesis air preparation system ozone, consisting of a compressor, a drying unit, an air reducer connected to an ozone generator, the ozone excess treatment system is equipped with a heating element and a catalyst, the filtration system consists of It consists of series-connected mechanical, sorption and membrane filters, sorption filters are multilayer and filled with sorbents of different structure and density.

 The drawing shows a block diagram of an installation for ultrapure water.

For a better understanding of the essence of the method, we consider its implementation on the example of water purification, information about the quality of which indicates constantly existing deviations of its quality from the standards, significant fluctuations in the levels of pollution and the composition of impurities of three types:
- microbiological pollution,
- organic compounds
- inorganic compounds of salt type and iron.

The process of water purification by ozonation begins with the preparation of air before the synthesis of ozone, because it is known how sensitive this process is to the presence of moisture. The following parameters are given to atmospheric air: pressure P = 0.6 + 0.1 kgf / cm ² , dew point no more than minus 55 ^o C and flow rate Q = 2.5 m ³ / h. This ensures the smooth operation of the ozone generator and positively affects the efficiency of the ozone synthesis process. The purified water is supplied to the reactor tank. At the same time, pre-sprayed ozone is supplied there. Passing through a layer of purified water, ozone enters into a chemical reaction with substances dissolved in water. Spraying ozone allows you to increase the area of treated water, which increases the yield of ozonated water. The reaction in water produces precipitation in the form of various oxides. Insoluble ozone is decomposed in two stages: I - heating to a temperature of at least 80 ^o ; II - decomposition on the surface of the catalyst. Treated with ozone water is fed to a three-stage filtration. To reduce salinity after a three-stage filtration, water is demineralized.

 The combination of ozonation with filtration and sorption on activated carbon makes it possible to destroy complex organomineral complexes, oxidizes and removes metals, accelerates the process of nitrification of ammonium nitrogen, and also serves for the oxidation and sorption of various dissolved organic substances that give water a taste and smell, and for other purposes.

 Filters loaded with activated carbon, regardless of fluctuations in the level of water contamination, serve as a permanent barrier to sorbed substances.

 Thus, the combination of ozonation and filtration on filters with different loads is the optimal technological solution to the problems of improving the quality of drinking water.

 To confirm the above, we offer the following table, which summarizes the results of a study of the quality of drinking water obtained by the proposed method.

 To implement the proposed method for producing ultrapure water, an installation is proposed that contains an air preparation system for ozone synthesis, consisting of a compressor 1, a receiver 2, a drying unit 3, an air reducer 4 connected to an ozone generator 5. On the receiver 2 installed alarm sensors 6 extreme pressure. The ozone generator 5, the ozone control sensor 7 in the air is connected to the reactor tank 8, which is a tank divided along the axis by a partition 9 into two communicating parts. The purified water 10 is pumped into the tank reactor 8 through a strainer 11, and ozone through a dispersing device 12. The tank reactor 8 is connected to an ozone neutralizer 13, consisting of an electric heater and a catalytic chamber. Behind the reactor tank 8, the ozonized water supply pump 14 feeds it into the filtration system, which consists of a mechanical 15, two sorption 16, 17 and membrane 18 filters. At the outlet of the membrane filter 18, an ozone control sensor 19 in water is installed. All purified water enters the storage tank 20, from where it enters the consumer.

 Installation for ultrapure water works as follows.

 The purified water is taken from the water conduit, pumped through the strainer 11 and fed to the tank reactor 8. At the same time, ozone is sprayed into very small bubbles through the dispersing device 12 and into the tank reactor 8, which enter the chemical reaction through the layer of water to be cleaned. with substances dissolved in it. As a result of the reaction, precipitates are formed in the form of various oxides that are deposited on the filters: the first stage is a filter 15 with quartz sand, the second and third are sorption filters 16, 17 with activated granular carbon of various structure and density, laid in several layers.

 To reduce salinity and correct the ionic composition of water after a three-stage filtration, water is sent to the membrane filter 18.

 The supply of demineralized water to consumers is carried out from the storage tank 20 of pure water.

 In addition, water from the storage tank 20 is supplied to flush the filters and to cool the ozone generator 5.

 Before entering the ozone generator, atmospheric air undergoes preliminary preparation: it is compressed by compressor 1 to P = 0.75 MPa, after opening the shut-off valve (not shown in the drawing), air enters receiver 2.

Then the air enters the air dryer 3 and acquires the parameters: T = 25 ^o C, dew point not higher than -55 ^o C. Passing through the air reducer 4, the air acquires the parameters: P = 0.06 + 1 MPa; T = 25 ^° C; Q = 2.5 m ³ / h; dew point - 55 ^o C.

The ozone neutralizer 13 is designed to decompose unreacted ozone after passing through a layer of treated water to sanitary standards before being selected into the atmosphere. This occurs in two stages: a) the gas is heated to a temperature of at least 80 ^o C; b) passes through the catalyst.

 The control system, consisting of 6 extreme pressure sensors-alarms, air control sensor 7, ozone in water control sensor 19 and many other units (not shown in the diagram), ensures uninterrupted water supply, control of its purification complex, monitoring of parameters and blocking from emergency situations.

 Currently, there is increased attention in the world to methods and means of obtaining clean drinking water. The proposed method and installation allows to achieve high efficiency of water neutralization from chemical pollution, to avoid the formation of toxic derivatives and go directly to filtration on filters with active loading.

Claims (2)

 1. A method of producing ultrapure drinking water, including the synthesis of ozone from air, passing it through a layer of treated water, treating excess ozone and filtering the water, characterized in that the air is pre-cooled and dried before ozone synthesis, the ozone is sprayed before passing through the water layer, processing excess ozone is carried out by its decomposition and heating and subsequent passage through the catalyst, and filtration is carried out in three stages, after which the water is demineralized.  2. Installation for producing ultrapure drinking water containing an ozone generator, a reactor tank with a longitudinal partition, a treated water supply unit, an excess ozone treatment system, a filtration and control system, characterized in that it is equipped with an air preparation system for ozone synthesis, consisting of a compressor, a drying unit, an air reducer connected to an ozone generator, the excess ozone treatment system is equipped with a heating element and a catalyst, the filtration system consists of a series connection mechanical, sorption and membrane filters, and sorption filters have a multilayer structure and are filled with sorbents of various structures and densities.

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