UA58327C2 - A process for water purifying - Google Patents

Abstract

A process for water purifying comprises processing the latter by ozone along with ultraviolet irradiation. At that the water is preliminarily processed by ozone.

Description

Description of the invention

The invention relates to the technology of natural and waste water purification using oxidants, and can be used to purify water from natural and anthropogenic organic compounds, in particular, from hard-to-oxidize and toxic micro-impurities.

A known method of water purification of surface water sources by treating them with ozone (ozonation) (Alekseeva

L.P., Draginsky V.L. Application of ozone for water purification of various water sources of Russia // Chemistry in the interests of sustainable development. - 1997. - T.5, Mo4. - P.365-374) (1|. Natural (river) 70 water containing humic substances (humic and fulvic acids), petroleum products (0.2-Zmg/dm), pesticides (0.001-0.6μg/dm) was subjected to purification 3) and synthetic surface-active substances (SPAR) (0.08-0.17 mg/dmU). Water treatment with ozone was carried out at a laboratory installation in a bubble-type reactor. The dose of ozone, depending on the concentration of impurities, was 2-20 mg/dm3 with a processing time of 8-15 minutes.

The degree of purification of water from humic substances by ozone was 6095 according to color, and 10-4095 according to permanganate oxidation. The concentration of anthropogenic micro impurities decreased on average from 2090 (petroleum products) to 40-42 95 (pesticides and SPAR) G11.

The disadvantage of method |1) is a low level of water purification from organic impurities of a natural and anthropogenic nature.

A well-known method of treatment of natural and wastewater using UV irradiation for the purpose of disinfection (Skurlatov I.Y.M., Shtam E.V. Ultraviolet radiation in the processes of water treatment and water treatment //

Water supply and sanitary equipment. - 1997. - Mob. - P.14-18) |2). With typical values of the dose of bactericidal radiation (16-40 mW -s/cm?) and its duration (several seconds), such treatment is not accompanied by a change in the chemical composition of the water. Therefore, the use of UV irradiation to purify water from organic impurities is not effective.

The closest analogue to the invention in terms of technical essence and the result that is achieved is the method of water purification with 9) ozone together with UV irradiation (OO 5/UV), described in the article (Photooxidation of pesticides with ozone and hydrogen peroxide in the preparation of drinking water! / V. V. Honcharuk, V. F. Vakulenko, A. O. Samsony-Todorov, etc. // Chemistry and technology of drivers. - 1995. - Vol. 17, Mo4. - P. 397-410) IZ. rch-

The essence of the method is as follows:

To implement the method, model solutions were prepared on tap water containing anthropogenic impurities, such as sim-triazine (atrazine, promethrin, zencor) and organophosphorus (metaphos) pesticides at a concentration of 0.05-0.1mg/dmU of each.

Processing of solutions was carried out on a laboratory installation, which includes an ozonator with a productivity of 1 g Oz/h, a bubbling reactor with a volume of 0.5 dm3, a source of ultraviolet radiation (a DRB-8 lamp) of the submerged type in a quartz casing. The rate of ozone delivery was equal to 1.5-2.9mg/dm.min, the intensity

UV radiation was 1.6 W/dm Z, the duration of water treatment was 10-15 minutes. The degree of water purification was controlled according to COD (International standard ISO 6060. Water quality. Determination of chemical oxygen consumption) "

ID and residual concentration of pesticides, which was determined by the method of gas-liquid chromatography (GLC) of IZI. The degree of purification of the model solution from pesticides (with their total concentration of 0.2mg/dmU, color with 2O0grad and COD 16bmg O/dm3) after O 5z/UV-treatment was 9495 - from simm-triazine and 9895 - from :z» organophosphorus pesticides. The degree of purification of the model solution with ozone together with UV irradiation according to COD was 52905.

The effectiveness of the known method |Z| was tested by us on natural water containing humic and fulvic acids and anthropogenic micro impurities (pesticides, SPAR).

The model solution was Dnieper river water (color ZOgrad, COD 25 mg O/dm Z) with 6 pesticide additives (atrazine, zencor, metafos, bazudin, baileton, tilt) in concentrations (4) of 0.1-0.29 mg/ dmZ (total concentration of 1.1 Ωg/dm З) and O0.2 mg/dm? of anionic surface-active substance - 50% sodium alkylbenzenesulfonate (ABS).

The treatment of the model solution (color ZOgrad, COD 27mg O/dm?, pesticide concentration 1.1Omg/dm U, "m ABS 0.2mg/dmU) with ozone together with UV irradiation was carried out in a bubble-type reactor (volume 4dm U) with a submerged source of UV radiation (lamp DB-15).The rate of ozone supply was equal to 1.bmg/dm Z.min, the intensity of UV radiation was 0.6W/dm3.

COD (CO 6060), residual concentration of pesticides (GRH) and ABS were determined in the purified solution

HF) (International standard ISO 7875/1. Water quality. Determination of surface-active substances. Part 1. Determination of 7 anionic surface-active substances by the spectrophotometric method with methylene blue.) 5). The degree of purification of the model water according to COD after O5/UV-treatment during ZOhv was 4095, according to pesticides - 5895, according to SPAR - 5090. 60 It follows from the obtained data that the application of the known method |З| for water purification, containing toxic (pesticides) and hard-to-oxidize (ABS) impurities in the presence of organic substances of natural origin (humic and fulvic acids), does not provide a high degree of water purification.

Thus, the main drawback of the known method of purification is the insufficient degree of purification of water from organic substances of natural (humic and fulvic acids) and anthropogenic (pesticides, SPAR) origin. 65 The invention is based on the task of improving the method of purifying water from organic impurities of a natural and anthropogenic nature due to the most expedient mode of joint use of O with and

UV radiation. The achieved result is expressed in a significant increase in the degree of water purification from the specified impurities.

To solve the problem, a method of water purification is proposed, which includes treatment of the latter with ozone along with UV irradiation, in which, according to the invention, water is pre-treated with ozone, and the mass ratio of ozone used at the stage of ozonation and O 5/UV treatment is (10 -40):(60-90), respectively.

We have shown that the sequence of water treatment processes, which is applied, first with ozone, and then jointly with /0 ozone and UV radiation at the mass ratio of ozone used at the ozonation stage and

O5/UV treatment, equal to (10-40):(60-90), respectively, creates conditions that ensure deep destruction of hard-to-oxidize anthropogenic micro impurities and humic and fulvic acids due to the most effective use of both ozone and UV radiation.

The method is implemented as follows:

The Dnipro water was treated with additives of pesticides and SPAR. The river water contained different concentrations of humic and fulvic acids, its color varied within 30-7Ograd, the COD value - within 25-45mMg

O/dm3. The model solution was Dnieper river water with additives of pesticide drugs (atrazine, zencor, metaphos, bazudin, baileton, tilt) at a concentration of 0.10-0.29mg/dm3 of each (total concentration of 1.1Omg/dm of U) and O0, 20 mg/dm? sodium alkylbenzenesulfonates (ABS).

The treatment of the model solution (color 30-7Ograd, COD 27-47mg O/dmU, pesticide concentration 1.10mg/dm, ABS 0.20mg/dm) was carried out on a flow-through installation, which includes serially connected ozonation reactors and O 5/UV treatments bubbling type with a submerged source of UV radiation (lamp DB-15) in the latter. The ozone-air mixture (OPS) was dispersed through a Schott filter located at the bottom of each reactor. Water was supplied to the first reactor in a direct flow from below, ozonized water from the upper part of the first reactor entered the upper part of the second reactor, and was removed from the bottom. The concentration of ozone (3

OPS was controlled by the iodometric method, the OPS supply rate was controlled using a gas meter

GOB-400. The dose of absorbed ozone was determined by the equation of the material balance of ozone in the gas phase at the inlet and outlet of the reactor. The total volume of the treated solution was 8.0 dm3. The rate of ozone supply was equal to 1.6-2.Zmg/dm Z.min, the intensity of UV radiation was 0.6W/dm?. The mass ratio of ozone used at the stage of ozonation and O5/UV treatment was (10-40): (60-90), respectively. with

Example of implementation of the method according to the invention: co

The processors were exposed to a model solution prepared on the natural water of the Dnipro River with the following indicators: color - 5Ograd, COD - 42mg O/dm3, concentration of pesticides - 1.1O0mg/dm With ABS - 0.2mg/dm3. The model CO solution was fed into the ozonation reactor from below at a rate of 0.27 dm C/min simultaneously with the feed of a portion of the OPS.

The ozonized solution through the connected upper nozzles of both reactors entered the Oz/UV treatment reactor, where it was subjected to simultaneous O treatment and UV irradiation. For this purpose, part of the OPS was fed into the reactor

O5/UV treatments from below. The purified solution was discharged through the lower pipe of the second reactor. The concentration of ozone in the OPS was 11 mg/dm3. The obtained OPS was distributed in such a way that the ratio of used ozone in the first and second reactors was 30:70. The dose of ozone supplied to the first reactor was 14.4 mg/dm, in the second - 33.bmg/dm, the absorbed ozone dose was 7.2 and 16.8 mg/dm, respectively. Samples of purified solution for determination of COD (СО 6060), concentrations of pesticides (GRH) and ABS (СО 7875/1) were taken after reaching a quasi-stationary water quality treatment regime (after changing the solution three times in the system).

The COD value of the purified model solution was equal to 21 mg O/dm?, the total residual concentration of pesticides - 0.18 mg/dmU, the concentration of ABS - 0.07 mg/dm Z. (The residual concentration of individual pesticides was (mg/dm): atrazine and zencor - 0.05, bailetone - 0.03, metaphos and tilt - 0.02, din base - 0.01.) because the degree of purification of the model solution by the indicated method according to COD was 5095, the total concentration of pesticides decreased by 8495, SPAR - by 7095 (example 4, table).

It was experimentally established that the optimal ratios of ozone used at the ozonation stage of O3/UV treatment, which are (10-40):(60-90), ensure a sufficiently high degree of water purification from

And pesticides - by 72-8595, from SPAR - by 53-7595 during the general purification of water from the amount of organic impurities, characterized by the COD value, at the level of 45-5295 (table, examples 1-6).

When the ratio of used ozone is reduced beyond the limit at the O z and O5/UV treatment stages, i.e. under 5 conditions of an insufficient amount of used ozone at the ozonation stage, a sufficient degree of water discoloration is not ensured, which leads to a decrease in the degree of water purification from organic impurities at the stage (F. O5/UV treatment due to inefficient use of UV radiation (table, example 8). If the ratio of used ozone increases beyond the limit at the stages of O with and O5/UV treatment, i.e. in conditions of insufficient amount of used ozone at the stage of Oz/UV treatment , there is a sharp decrease in the degree of purification of water from hard-to-oxidize impurities (pesticides, SPAR) and the depth of decomposition of humic and fulvic acids, estimated by COD (table, example 7).

The advantages of the proposed method of water purification in comparison with the known method are as follows:

Implementation of the proposed method ensures an increase in the degree of water purification from anthropogenic impurities: pesticides - from 58 to 72-8595, i.e. by 14-2795, SPAR - from 50 to 53-7595, i.e. by 3-2595, with a 65 increase in the degree of general water purification from of organic impurities according to COD - from 40 to 45-5295, i.e. by 5-12905.

The use of the proposed method provides effective and reliable purification of natural waters while changing the qualitative and quantitative composition of its organic impurities in a wide range.

The advantage of the proposed method is also its environmental safety, absence of secondary pollution, sludge, etc.

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Formula of the invention

The method of water purification, which includes the treatment of the latter with ozone together with ultraviolet irradiation (O5/UV), which differs in that the water is pre-treated with ozone, and the mass ratio of the ozone used at the stage of ozonation and O5/UV treatment is (10-40): (60-90), respectively. what-

From school

Official bulletin "Industrial Property". Book 1 "Inventions, useful models, topographies of integrated microcircuits", 2005, M 1, 15.01.2005. State Department of Intellectual Property of the Ministry of Education and Science of Ukraine. (ee)

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