RU2293708C2 - Method of purification and deconamination of the waste waters - Google Patents

Abstract

FIELD: environmental protection; methods of purification and decontamination of the waste waters.

SUBSTANCE: the invention is pertaining to the method of purification and decontamination of the waste waters with application of the electrotreatment and may be used for the local purification and decontamination of the waste waters of the enterprises of the biological industry, patient care institutions, the tuberculous and infectious diseases hospitals. The method of purification and decontamination of the waste waters consists, that the waste water is subjected to the sedimental purification with usage of the aluminum polyoxychloride as the reactant, then it is filtered by the screen with the grainy load - silicicated calcite with the subsequent gating of the clarified waste water through the anode chamber of the membrane electrolyzer, filtration in the grainy aluminum- manganous catalyst and gating through the cathode chamber of the membrane electrolyzer. The water gating of the water is conducted in the electrical field intensity of 500-600 V/m with the rate of 15-18 m/h, further the purified water is subjected to the decontamination by the ultra-violet radiation, and the extracted sediment is subjected to the thermal treatment at the temperature of 110-120°C, the pressure of 0.15-0.20 MPa within 0.2-0.3 hours. The technical result of the invention is reduction of the power inputs, decrease of the metal consumption of the equipment, provision of high-degree of the purification and decontamination of the waste water and the sediment.

EFFECT: the invention ensures the reduced power inputs, the decreased metal consumption of the equipment, provision of the high-degree of the purification and decontamination of the waste water and the sediment.

4 cl, 3 ex, 1 dwg, 4 tbl

Description

The invention relates to a combined technology for wastewater treatment and disinfection using electric treatment and can be used for local wastewater treatment of biological industry enterprises, medical institutions, tuberculosis and infectious hospitals.

A known method of disinfecting a liquid, which consists in the fact that the wastewater is preheated in a heat exchanger due to the heat of the treated wastewater to a temperature of 50-60 ° C, and then the water is heated to 120-140 ° C and disinfected for 3-5 minutes [ one].

The disadvantage of this method is the high power consumption. A known method of simultaneous electrocatalysis and electrocoagulation. After the electrocatalytic treatment and sedimentation for 24-30 minutes, the adsorption-catalytic purification of wastewater by filtration through a layer of adsorbent-catalyst [2].

The disadvantage of this method is also the high energy consumption.

A known method of treating sludge from domestic and / or industrial wastewater, including heat treatment of a suspension of sludge, separation of liquid and solid phases, after the end of heat treatment of the suspension at a temperature of 150-220 ° C, it is treated with alkali to a pH of more than 10 and an oxygen-containing gas at a pressure of 1, 5-5.0 MPa for 20-180 min, after which the pressure is reduced to atmospheric and cooled to a temperature of less than 100 ° C, the suspension is fed for separation with the separation of the organomineral complex in the form of a liquid phase and an insoluble solid residue, s heavy metal salt [3].

The disadvantage of this method is the irrational overstatement of temperature and pressure, which leads to high energy costs.

The closest technical solution is a method for wastewater treatment from suspended solids, including wastewater clarification by settling with separation of clarified liquid from sludge, filtration and ultrafiltration of clarified liquid at a flow rate of 3-8 m / s and a pressure of 0.35-0.55 MPa , the return of the concentrate to the clarification stage under a layer of clarified liquid. In this case, the sludge is subjected to extraction and drying, and the water obtained during the extraction of the sludge is returned to the clarification stage [4].

The disadvantages of this method are the relatively high energy consumption for creating a high pressure for the ultrafiltration process, high metal consumption, the absence of the effect of extracting dissolved organic substances and ammonium nitrogen, and the absence of disinfection of water and sediment.

The problem solved by the invention is to reduce energy costs, reduce the intensity of equipment, providing a high degree of purification of water from dissolved organic substances and ammonium nitrogen, disinfection of water and sludge.

This problem is solved by the fact that in the method of purification and disinfection of wastewater, including purification of water by sedimentation in sumps, followed by filtering, in the invention, the waste water is purified by reagent sedimentation in sumps with thin-layer blocks, followed by filtration on filters with granular loading, then clarified wastewater is passed through the anode chamber of the membrane electrolyzer, after which the purified water is disinfected with ultraviolet radiation, and the electric treatment in the electrolyzer is carried out when water is passed in an electric field with an intensity of 500-600 V / m at a speed of 15-18 m / h, and the sediment extracted by sedimentation is sent to heat treatment at a temperature of 110-120 ° C for 0.2-0.3 hours under pressure of 0.15-0.20 MPa. In this case, aluminum polyoxychloride is used as a reagent for sedimentation purification, silicified calcite is used as a granular charge for filters, and a manganese-aluminum catalyst is used as a catalyst.

The drawing shows a schematic diagram of the technology for wastewater treatment and disinfection.

The circuit diagram includes a wastewater storage device 1, a grate 2, a pumping station 3, a reagent farm 4, a sump with shelf units 5, a filter with a granular charge 6, a membrane electrolyzer 7, a filter with a catalyst 8, ultraviolet lamps 9, a sludge storage tank with thermal electric heaters 10.

Wastewater treatment is carried out as follows. The initial wastewater is accumulated in the wastewater reservoir (1), after which large impurities are removed and the pumping station (3) is fed to the reagent treatment by sedimentation using aluminum polyoxychloride as a reagent, then the wastewater is filtered on filters (6) with a granular charge - siliconized calcite, then the clarified water is treated by passing wastewater through the anode chamber of the membrane electrolyzer (7), followed by filtration in a manganese-aluminum catalyst (8), then wastewater lowered through the cathode chamber, the electric treatment is carried out in electrolyzers (7) by passing water in an electric field with an intensity of 500-600 V / m at a speed of 15-18 m / h, then the purified water is disinfected with ultraviolet radiation (9), the sediment extracted by sedimentation is sent to heat treatment at a temperature of 110-120 ° C, pressure 0.15-0.20 MPa for 0.2-0.3 hours.

The processing principle consists in the fact that the combined use of catalysts and electrically generated oxidizing agents makes it possible to use the oxidizing power of reagents more fully and more expediently, to achieve deep mineralization of organic substances. In the presence of a catalyst, the decomposition of active chlorine is accelerated with the formation of reactive atomic oxygen, which causes an increase in the rate and depth of mineralization of organic substances.

Thus, only part of the waste fluid (waterlogged sludge) is subjected to heat treatment, which reduces energy costs for disinfection.

For the feasibility study of the method, the following experiments were carried out.

Example 1. Conducted cleaning and disinfection of domestic wastewater, depending on the filtration rate at an electric field of 500 V / m. The results are shown in table 1.

Table 1 Name of indicator unit of measurement Source water Purified water at a filtration rate, m / h 10 fifteen eighteen 23 BOD _p * mg O ₂ / l 273 2,4 2.6 3.0 3.8 Ammonia nitrogen mg / l 31 eleven 12 fourteen 16 E. coli CFU / 0.001 ml 1 · 10 ³ 34 36 40 44 Sulfite-reducing clostridia CFU / 1.0 ml 24 not detected not detected not detected not detected * BOD _p - complete biological oxygen consumption

T.O. at a filtration speed of 18 m / h, a BOD value of _p = 3.0 mg / l is achieved, which corresponds to the MPC of fishery reservoirs (MPC _pkh ). At a filtration speed of 15 m / h, water quality indicators are improved. Lower filtering speeds are impractical due to the increase in the metal consumption of the equipment and energy costs for cleaning and disinfecting water.

Example 2. Conducted cleaning and disinfection of domestic wastewater, depending on the electric field at a water filtration rate of 18 m / h The results are shown in table 2.

table 2 Name of indicator unit of measurement Source water Purified water at field strength, V / m 400 500 600 700 BOD _p mg O ₂ / l 273 4.1 3.0 2.7 2,5 Ammonia nitrogen mg / l 31 eighteen fourteen eleven 5 E. coli CFU / 0.001 ml 1 · 10 ³ 74 40 25 13 Sulfite-reducing clostridia CFU / 1.0 ml 24 not detected not detected not detected not detected

T.O. reduction of the electric field intensity less than 500 V / m increases the BOD _{n pi} more MACs, increased more than 600 V / m leads to an increase in cost of cleaning and disinfecting water.

Example 3. Sediment recovered sediment with a moisture content of 98% was subjected to heat treatment disinfection. The results are shown in table 3.

Table 3 Name of indicator unit of measurement Source water Disinfected sediment 110 ° C, 0.2 h, 0.15 MPa 120 ° C, 0.3 h, 0.20 MPa E. coli CFU / 0.001 ml 1 · 10 ³ lack of lack of Sulfite-reducing clostridia CFU / 1.0 ml 24 lack of lack of

A 100% disinfection effect has been achieved. Pathogenic microorganisms may be present in the wastewater, therefore, a 100% disinfection effect should be guaranteed by the established mode of sludge treatment.

Technical and economic comparison of the options of the prototype method and the invention are shown in table 4.

Table 4 The name of indicators Prototype method The proposed method Water Consumption, m ³ / h 1,0 1,0 The output of purified water, m ³ / h 0.9-0.05 1,0 BOD _p , mg / l no information 3.0 The cleaning effect,% 92.4-96.5 98.9 Pressure in the system, MPa 0.35-0.55 0.2-0.3 Energy intensity, kW • h / m ³ 4,5-5,0 0.8-0.9 Metal consumption of equipment, t / m ³ 0.8 0.25

T.O. the proposed method is more attractive in all respects. Special attention should be paid to the additional functions of the proposed method, namely, disinfection of water; a 98.9% decrease in the amount of dissolved organic substances determined by the BOD parameter _p ; reduction of dissolved ammonium nitrogen.

LITERATURE

1. USSR patent 952773, MKI C 02 F 11/18. Device for disinfecting liquids. // Tikhontsov A.M., Korobochka A.N., Kokorin A.V., Kiryanov S.A. / B.I. - 1982. - No. 31.

2. Catalysis Group of Companies “New Catalysts and Resource-Saving Catalytic Technologies for Modern Russia”. Angarsk, 2003, 48 pp.

3. RF patent 2070165, IPC C 02 F 11/18. A method of treating sludge for domestic and / or industrial wastewater. // Kalinin V.P., Kononov V.E., Trofimov V.A., Shipov V.P. / B.I. - 1996. - No. 34.

4. RF patent 2001663, IPC B 01 D 61/16, C 02 F 1/46. The method of wastewater treatment from suspended solids. // Kuperman B.C., Voznesensky S.D., Ganichev A.V. et al. / B.I. - 1993. - No. 39.-40.

Claims (4)

1. The method of purification and disinfection of wastewater, including water purification by sedimentation in sedimentation tanks, followed by filtration, characterized in that the wastewater is purified by reagent sedimentation in sedimentation tanks with thin-layer blocks, followed by filtration on filters with granular loading, then clarified waste water is passed through the anode chamber membrane electrolyzer, filtered in a granular catalyst and passed through the cathode chamber of the electrolyzer, after which the purified water is disinfected with ultraviolet radiation and, moreover, the electric treatment in the electrolyzer is carried out by passing water in an electric field with a strength of 500-600 V / m at a speed of 15-18 m / h, and the sediment extracted by sedimentation is sent to heat treatment at a temperature of 110-120 ° С for 0 2-0.3 hours under pressure 0.15-0.20 MPa. 2. The method according to claim 1, characterized in that as a reagent for sedimentation purification using aluminum polyoxychloride. 3. The method according to claim 1, characterized in that silica calcite is used as a granular filter load. 4. The method according to claim 1, characterized in that the catalyst used is a manganese-aluminum catalyst.