RU2051128C1 - Method for production of drinking water - Google Patents

Abstract

FIELD: production of drinking water. SUBSTANCE: water is filtered and ozonized. The oxidizing-reducing potential of cleaned water is under continuous inspection for adjusting the consumption of ozone-water mixture for preliminary ozonizing. Said consumption is adjusted in inverse proportion to the oxidizing-reducing potential corresponding to the standard covering the drinking water. EFFECT: higher efficiency. 1 dwg

Description

 The invention relates to water supply, in particular to the processing of water from surface sources in drinking water supply systems, for example, on ships.

 A known method of purifying drinking water with ozone in a small-sized installation, according to which the oxidation-reduction potential (ORP) of the controlled water is monitored and, when the ORP decreases below a predetermined level, include an ozonizer and a cooling device for additional water treatment to the required quality indicators, i.e. a device that controls the ORP indicator of water is used as a sensor for turning water treatment devices on and off and a device for dispensing water to a consumer.

 The disadvantage of this method is the frequency of tempering of conditioned water. The method involves the processing of already purified water and cannot be applied to untreated river water.

 Closest to the invention is the method underlying the operation of the station for the preparation of drinking water on ships. Seawater is fed to a reaction vessel for processing, in which it is diluted with an ozone-water mixture for carrying out oxidative and mass transfer processes, then the water is filtered and fed through an ejector to a contact column, where secondary ozonation (post-ozonation) is performed. At the same time, part of the unreacted ozone-water mixture from the contact chamber is taken into the reaction vessel for preliminary ozonation.

 The disadvantages of the method are the low reliability under conditions of varying concentrations of contaminants in the source water and the inefficient use of ozone in the water treatment system. Given the changing contamination of the source water, it is very difficult to control the ozone flow rate and it is only in a narrow range of pollution concentrations that it is possible to organize optimal treatment in individual water treatment operations, which reduces the quality of water treatment in general.

 The purpose of the invention is to increase the efficiency of use of ozone and the reliability of treatment with changing contamination of the source water.

 The goal is achieved by the fact that in the method of preparing drinking water of multi-stage purification, including filtering and subsequent ozonation with selection of part of the ozone-water mixture for preliminary ozonation before purification, continuous monitoring of the oxidation-reduction potential of the purified water is carried out, by which the ozone-water mixture is regulated for preliminary ozonation, moreover, flow control is performed inversely proportional to the ORP beyond a predetermined interval and ORP values corresponding to standard water quality.

 The proposed method allows to redistribute ozone between the operations of preliminary and subsequent ozonation, depending on the initial pollution of water, which allows more efficient use of the oxidizing agent in individual operations, to ensure reliable treatment of water when changing its initial pollution. The regulation operation introduced into the method allows increasing the consumption of ozone-water mixture for preliminary ozonation while increasing the contamination of the source water and at the same time increasing the residence time of the water for postzoning operations, which enhances the oxidation processes in both operations and intensifies the process of water purification as a whole.

 It is known that with an increase in pollution in controlled water, its redox potential decreases, and the standard water quality corresponds to a well-defined range of ORP values. In this regard, the proposed method provides for controlling the flow of ozone-water mixture for preliminary ozonation in inversely proportional to the ORP beyond a predetermined range of values corresponding to standard water quality. The range of ORP indicator values, which determines regulation, is set based on the guaranteed water quality.

 The drawing shows a diagram of a ship station for the preparation of drinking water.

 The station contains a pump 1, a filter unit 2, an ozonator 3, an ejector 4, a contact column 5, in which there is a mass transfer zone 6 and a reaction zone 7, a circulation pipe 8 for removing particles of the ozone-water mixture into the pipeline before the filters, a potentiometric device 9 for monitoring oxidation the recovery potential of the purified water, connected by the output signal to the flow controller 10, which can be installed either in the circulation pipe 8, as shown in the diagram, or on the pipe 11, which discharges the purified water into the cut rvuar pure water (not shown). Depending on the flow rate, composition and concentration of contaminants, the water treatment plant may include other water treatment devices modules (for example, a coarse water purification module by sedimentation).

 The preparation of drinking water by the proposed method is as follows.

 After rough cleaning, it is subjected to preliminary ozonation by diluting it with an ozone-water mixture, which is supplied through pipeline 8. In addition to the maso-exchange processes, ozone is dissolved in the water, and the formation of suspensions is intensified. Subsequent cleaning-filtering ensures the separation of suspended solids in the loading of filters 2. Next, the purified water is supplied for decontamination by ozonation in a contact column 5. Ozone is fed into the water through an ejector 4 from ozonizer 3. In the mass transfer zone 6 of column 5, ozone is mixed with water. Part of the ozone-water mixture from this zone 6 through the pipeline 8 is discharged into the pipeline before the filters 2 for pre-filtering. This flow rate is regulated depending on the quality of the purified water by the flow regulator 10. Another main stream of ozone-water mixture passes into the reaction zone 7, column 5, where the further disinfection process takes place. In the discharge pipe 11, the quality of the purified water is monitored potentiometrically by a device 9, which continuously measures the redox potential of the purified water.

 The decrease in the ORP of the treated water below the minimum value of the specified interval indicates a deterioration in its quality and a violation of the purification process. In this case, the signal from the potentiometric device 9 includes the actuator of the controller 10 to increase the flow rate of the ozone-water mixture in the pipeline 8. The oxidation processes in the treated water and the separation of pollutants on the filters are amplified 2. At the same time, the flow rate of the water in the reaction decreases zone 7 of the contact column 5, increases the residence time of water in this zone, which provides better disinfection of water. Thus, the redistribution of the ozone-water mixture by regulating the flow rate in the pipeline 8 simultaneously intensifies two processes: preliminary ozonation before filtering and final disinfection of water postzonation.

 When improving the quality of purified water, its redox potential increases. The increase in ORP above the maximum value of the specified interval leads to the actuation of the actuator of the controller 10 and a decrease in the consumption of ozone-water mixture for preliminary ozonation.

 As mentioned above, to implement the method, you can use the controller installed in the discharge pipe 11. In this case, if the water quality deteriorates and the ORP decreases below the minimum value of the specified interval, this controller should increase the resistance in the discharge pipe 11, reducing the yield of purified water and increasing the consumption of ozone-water mixture in the pipeline 8 for preliminary ozonation.

 PRI me R. Water from the river is taken to the ship’s water treatment plant, where it is subjected to rough treatment, then preliminary ozonation, filtration and re-ozonation by ejection of ozone into the reaction column. At the column outlet, the redox potential of the purified water is continuously monitored. When ORP decreases below 650 mV (level) ORP of drinking water of standard quality, the regulator increases the supply of ozone-water mixture for preliminary ozonation, enhancing oxidative and mass transfer processes before filtering. At the same time, the residence time of water in the reaction zone of the contact column is increased, and therefore, the disinfection of water is intensified. The quality of purified water is restored. When the ORP of purified water reaches a predetermined interval, for example, 700 MV, the controller is activated to reduce the consumption of ozone-water mixture supplied to preliminary ozonation. The process continues.

 The method provides reliable water purification for drinking water supply in the conditions of changing its initial pollution.

Claims (1)

 METHOD FOR PREPARING DRINKING WATER, including filtering and subsequent ozonation with the selection of part of the ozone-water mixture for preliminary ozonation before filtering, characterized in that the consumption of the ozone-water mixture for preliminary ozonation is controlled in inverse proportion to the value of the redox potential corresponding to the standard of drinking water.

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