SU842042A1 - Method of water purification from suspended substances - Google Patents

Description

The invention relates to the field of water purification from suspended substances and can be used in the purification of drinking and waste waters.

For water supply to populated areas and industrial enterprises, surface water sources are often used, the waters of which contain colloidal and coarse dispersed substances, as well as bacteria, plant and animal organisms.

Before use, the water is clarified in settling basins, clarifiers with suspended sediment and filters.

Wastewater from urban sewage and sour enterprises must also be cleaned in settling tanks before discharge into reservoirs in order to protect the pollution of natural water bodies.

Known methods for the nsification of river and sewage clarification using iron salts, aluminum, starch and its compounds, sodium alginate, polyox, polystyrene | sodium, sodium salts of polyacrylic and methacrylic acid, VL-2, polyacrylamide, K-4, etc. Jl and 23.

The disadvantage of such methods is that when the content of suspended substances in water is less than 500-1000 mg /

and at pH less than 6.5-7, pretreatment of water with low molecular weight electrolytes, such as aluminum sulphate, is required. For water with a suspended matter content of more than 1000 mg / l with self-applied flrulant, the purification rate is lower and requires a long time to stand.

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The closest to the proposed technical essence and the achieved result is a method of water purification from suspended substances using as a flocculus a water-soluble polymer based on fumaric acid and acrylamide (FAA) with a ratio of 1: 4 .31

This flocculant (FAA) acts more efficiently than widely used polyacrylamide, does not require additional treatment with coagulants, however, its effectiveness is often insufficient, for example, in the preparation of drinking water.

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The purpose of the invention is to increase the degree of water purification from suspended substances.

The goal is achieved by the treatment of water with a polymer with a ratio of fumaric acid and acrylamide 1: 6-10, preferably in an amount of 0.01-1.0 mg / l. The study of the flocculation of these polymeric electrolytes at different ratios of the monomerically units in the composition of macromolecules 1: 1, 1: 4, 1: 8, 1:12, 1:16 shows that under the same conditions the polymer that is obtained is the most brightening at a ratio of 1: 8 (FAA-3), an increase or decrease in the macromolecular composition of the molecule of acrylamide units (greater than 10 or less than 6) leads to a deterioration of the flocculating ability of the dimensional electrolyte. The effect of clarification with the same doses of FAA-3 (1: 8) is greater than with other ratios. Comparative data on the relative efficiency are given in Table 1. Table The method for purifying water from suspended substances is carried out as follows. Water containing suspended solids (20-100000 mg / l) is injected with a solution-copolymer based on fumaric acid and acrylics (ratio of fumaric acid and acrylamide 1: 8, intrinsic viscosity 8.24) and intensively stirred for 30-60 seconds, after which one of the following methods for separating the precipitate from water is carried out. 1. Production of settling in a cylinder with a diameter of 200 mm and a height of 1 m for 15 minutes. At a depth of 0.5 m, samples are taken and the residual amount of suspended substances is determined. 2. A vertical sump is placed on the model along the top of the central pipe with a diameter of 20 mm (model diameter 200 mm, height 3 m). The clarified water is taken from above and the residual amount of suspended solids is determined. 3. Bottom of the model of clarifiers with suspended sediment diameter of 200 mm and height of 3 m is supplied. Clarified water is taken from above, suspended sediment is withdrawn from nozzles at a depth of 1.5 4. To water containing vzveigennye substances up to 50 mg / l, a flocculating solution is introduced and mixed vigorously for 30-60 ° C, then fed to a fast filter model with a diameter of 56 mm, a height of 2 m, loaded with quartz sand with an effective diameter of 1 mm. The optimal doses of flocculant for administrations 1-3 are, mg / l: Weighted Flocculant substances 20-1000.01-0.3 100-5000.3-0.5 500-1000000.5-1.0 Optimal doses of flocculant for administration 4, 0.01-0.05 mg / l. The proposed method of water purification in steps 1 and 2 with FAA-3 increases the clarification of water by 2 times and in receptions 3 and 4 increases the clarification of water by 1.5 times compared to the purification of water with FAA, obtained on the basis of fumaric acid and acrylamide with a ratio of 1 : 4 under similar conditions. Example 1. With a suspended solids content of 2200 mg / l and a flocculant FAA-3 dose of 0.5 mg / l, intake 1, the residual suspended solids in water are 12-15 mg / l, and with known FAA 40 mg / l. Example 2. With a suspended matter content of 4800 mg / l with a flocculant dose of FAA-3 of 0.5 mg / l, taking 1 the residual amount of suspended solids is 20 mg / l, and with known FAA it is 50 mg / l. Example 3. With a suspended solids content of 12000 mg / l and a flocculant dose of FAA-3 1 mg / l, intake 2, the residual amount of suspended solids in water is 300 mg / l, and with known FAA, 60 mg / l. Example 4 With a suspended matter content of 980 mg / l in water and a flocculant FAA-3 dose of 0.5 mg / l as received 3 at a speed of upward movement of water of 1.2 mm / s, the residual amount of suspended matter is 3-4 mg / l, and with the known FAA 20 mg / l. EXAMPLE 5: When suspended solids are 30 mg / l in water at a FAA-3 dose of 0.05 mg / l, take 4 at a filtration rate of 14 m / h, the amount of suspended solids in the filtrate is 0.5-1. mg / l, and with known FAA 2-3 mg / l. Due to the high viscosity and molecular weight of flocculant FAA-3 for purification of suspended solids from water, the effect of water clarification is the same with equal doses of reagents (FAA and FAA-3), and to achieve the same degree of purification of the FAA-3 dose, than the FAA and are shown in table 2.

Table 2, under the same conditions, FAA-3 (1: 8) works effectively within the range of injected doses of 0.01-14 mg / l, and (1: 1) within 0.5-2 mg / l, (1: 4) in the limit of 0.3-4 mg / l, (1:12) within 0.55 mg / l, (1:16) within 1-6 mg / l. Thus, the technical and economic advantage of the proposed method of purifying water from suspended solids is that, as compared with the known method, all technological processes of water clarification intensify: the sedimentation rate of suspended solids in the settling tanks increases, the speed of the upstream water flow increases clarifiers with suspended sediment and the rate of filtration of water. All these processes are also characterized by an increase in the degree of purification by a factor of 1.5-3, an expansion in the range of doses of use of floccules.

Claims (3)

This FAA-3 and the possibility of suspended substances in a wide range of pH (3-12) treated water. Claim 1. Method for purifying VOD1.1 from suspended solids by treating water with a water-soluble flocculant polymer based on fumaric acid and acrylamide, followed by separating the resulting precipitate, characterized in that, in order to increase the degree of purification, water treatment is carried out with a fumaric ratio acids and acids lida 1: 6-10. 2. Method POP.1, characterized in that the polymer is introduced in an amount of 0.01-1.0 mg / l. Sources of information taken into account in the examination 1. Babenkov E. D. Water purification with coagulants. M., Science, 1977, p. 72-76. 2. Weitser Yu. I., Mints D. M. Water-soluble flocculants in water purification processes. M., stroiizdat, 1975, pp.24 - 36. 3. Asanov A. and others. Clarification of natural turbid waters with the help of flocculants. Collection of scientific papers of Tashkent University, 1977, W 539, p. 91-94.