SU1134551A1 - Method for clarifying low-turbidity water - Google Patents

Abstract

Ь THE METHOD OF LIGHTING SMALL WATER, including the introduction of mineral turbidity, aluminum sulphate and flocculant, followed by settling, distinguishing and c. By the fact that, in order to increase the degree of clarification and reduce the duration of the process, a mixture of filter pearlite and crushed quartz sand, taken in a ratio from 2: 1 to 1: 1, is used as a mineral muddy. 2. The method according to claim 1, wherein the blending agent is introduced in an amount of 7-10 g / l. 3. The method according to claim 1, of which is due to the fact that, after settling, a precipitate is stirred up

Description

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The invention relates to methods for purifying natural waters, preferably low-turbid waters of mine wells.

A known method of purifying water from suspended impurities, which consists in adding coagulant (flocculant) to it and periodically precipitating a coagulated suspension in cycles: supplying water to a sump - settling - discharging purified water of water c.

The disadvantage of this method is that the processes of flocculation and precipitation of coagulated suspension during the processing of very thin (up to 100 mg / l suspended impurities) water flow slowly, the sump capacity decreases sharply, and the purified water contains significant residual amounts of suspension.

A known method of intensifying the process of continuous purification of low-turbid water by adding to it a mineral mud (clay, calcium carbonate, quartz sand, cement, etc.) 21,

The implementation of the method leads to economy of reagents and acceleration of clarification, however, the mineral opacifier is used only once, as a result of which large quantities are required. Increasing the opacifier dose necessary to intensify the settling 5 is possible only up to a certain maximum value (from up to 2 g / l depending on of the type of sludge) that would not lead to a higher consumption of coagulant (flocculant) and would not cause a significant increase in the volume of sediment,

The closest to the proposed technical essence and the achieved result is a method of clarifying low-turbid water, including the introduction of mineral turbidity, aluminum sulphate and polyacrylamide, followed by separation of the resulting precipitate. In order to intensify the separation of suspended impurities, up to 2 g / l of micro sands with a particle size of 20-100 µm are added to the treated water. The waste microsand is subjected to regeneration by separation from the coagulated suspension in a hydrocyclone. The residual content of suspended substances according to a known method

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is 8-12 mg / l after 1-1.5 hours of sedimentation of Gs.

The disadvantages of this method are the low degree of clarification and the increased duration of the clarification process.

The purpose of the invention is to increase the degree of clarification and reduce the duration of the process. 10 This goal is achieved in that according to the method of clarifying low-turbid water, including the introduction of mineral turbidity, aluminum sulphate and flocculus 15 and followed by settling, a mixture of filter pearlite and crushed silica sand, taken in a ratio of 2: 1- eleven. 0 The opacifier is added in an amount of preferably 7-10 g / l.

After settling, sediment is stirred up.

The essence of the proposed method 5 is as follows.

Before the start-up of the batch tank, large amounts of mineral opacifier of a certain composition are added to its operation. When serving in the sump

The coagulated water (flocculant) treated is clouded by the opacifier, and after the water supply is stopped, the coagulated suspension separates into the sediment. As a result of the rapid growth of suspended flakes and consolidated precipitation, a high rate of clarification of water is achieved,. dramatically improving its quality and reducing the need for reagents.

All subsequent water treatment operations in the mode of filling the sump with water - upholding emptying is carried out with vzmuchivaniem and using all the volume of previously accumulated sediment. At the same time, sedimentation of sedimentation is achieved either by supplying water from bottom to top or by erosion by a stream of water5 supplied from top to bottom.

After 10-15 cycles of settling, the accumulated sediment is partially removed. Moreover, the gradual replacement of the slurry suspension with a coagulated slurry suspension, due to recrystallization and compaction of the suspension, with the results of 3

no further purification of water has any negative effect.

Example 1. In a sump of 1 m in height and a useful volume of 10 liters, 80 g (8 g / l) of mineral mud are added: bentonite, perlite filter, crushed quartz sand, as well as their mixtures in different ratios.

From top to bottom, river water with a temperature of 13 ° C and a suspended matter content of 89.6 mg / l is poured into the settling tank. During the filling of the settler, 40 mg / l of aluminum sulphate and 0.7 mg / l of PAA are added to the water.

The results of the treatment of water containing 89.6 mg / l of suspended substances with different opacifiers at a dose of ul aluminum sulphate 70 mg / l and a dose of PAA of 0.7 mg / l are given in Table. one.

In tab. Table 2 shows the results of the treatment of water containing 89.6 mg / l of suspended solids, with mutants of different composition at a dose of 10 g / l of opacifier, a dose of 40 mg / l of aluminum sulfate and a 0.7 mg / l PAA dose.

From the data given in table. 1 and 2, it follows that the use of mud as clay (kaolin, bentonite), filter perlite and crushed quartz sand in different quantities does not allow for an increase in the degree of water purification within a reasonable period of time. Coagulation and sedimentation of clay particles proceed slowly. Phyctertrolite precipitates faster, but a part of it floats on the surface of sedimentary water, deteriorating its quality. Crushed quartz sand precipitates before the coagulation process is completed.

The use of mixtures of clay and filter perlite, clay and crushed silica sand in different proportions does not provide an increase in the degree of clarification of water. This is possible only when using a mixture of filter perlite and crushed quartz sand in the ratio of 2: 1-1: 1.

Example 2. In the sump of the same design put different amounts of opacifier - a mixture of filter-perlite and crushed quartz sand in a 1: 1 ratio. From the bottom up, the settling tank is filled with river water containing 89.6 mg / l of suspended solids and temperature

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13C. 40 mg / l of aluminum sulfate and 0.7 mg / l of PAA are added to the inlet of the settling tank.

The results of water purification, depending on the dose of turbid are presented in table. 3

Anakhshz data tab. 3 shows that the process of clarification is most effective at doses of opacified bodies of 7-10 g / l. When adding a turbid in the amount of less than 7 g / l, due to the absence of the effect of consolidated sedimentation of the suspension, the degree of clarification of the water does not increase even

5 with a long standing. When a cloud is added in an amount of more than 10 g / l, the process of consolidated sedimentation of the suspension slows down due to overly constrained conditions,

0 precipitation, which is also reflected in the degree of clarification of water over time. Thus, the use of filter perlite and crushed quartz sand as a clouding mixture

5 in the ratio of 2: 1-1: 1 in the amount of 7-10 g / l allows to reduce the residual content of suspended matter in low-turbid water from 8-12 mg / l (by a known method) to 2.6-3.0 mg / l , wherein

0 reducing the process time from 1, 5-2 hours to 30 minutes.

Example 3. Analogous to example .1, but PAA, BA-2, PDMAEMA, PVA,

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in tab. 4 shows the results of the treatment of water containing 89.6 mg / l of suspended solids, filter-perlite-crushed quartz sand clutter (10 g / l) in a 1: 1 ratio, and various flocculants with a dose of aluminum sulfate 40 mg / l.

From tab. 4 it follows that the optimal dose of flocculant is 1-1.5 mg / l and the most effective is PAA, but also when using other floc. You can get satisfactory results on the quality of clarified water.

Technical and economic advantages of the proposed method consist in increasing the productivity of a water treatment plant by 3-4 times, reducing the residual concentration of suspended matter in settled water by 5-10 times, reducing the consumption of coagulant by 2.5 times and the consumption of flocculant by 30%. Indicator 1 I Residual suspended matter, mr / l, in water after .min 522.1 1518.2 3016.3 Indicator Residual suspended matter, mg / l, in water through 15 wl FIF of opacifiers: Kaoli: FShtr-per14, 2 12.7 liter18.2 Dropped kaolin: 12.4 13.0 quartz sand 18.1 Filter-perlite: crushed quartz pe8, 1 3.7 juice14.0

Dose clutter, g / l Indicator 0.5 L O | s, 0

Residual suspension, mg / l, 3 water after, min

five

15

thirty

Table3

7,0 4,0 3,8 4,9 7,1 6,2 3,2 2,7 4,2 6,8 5,8 3,0 2,6 4,0 6,1 Bentonite Perlite filter Crushed quartzDose muddle, g / l 5 10 I 20 1 2 I 10 I 20 I 1- 2 I 10 bo 21.8 16.5 18.3 17.0 17.2 14.8 16.1 27.5 30.5 25.7 23.9 17.4 11.9 12.1 14.3 14.3 12.0 10.4 27.1 25.7 22.2 22.4 12.1 8.2 9.93 UZ ° P, 1 10.4 8.7 9.1 21.2 19.3 20.3 18.7 VT-TMNNHx M - JM -V "M IW-". "",, ".M.". ..... "The ratio of components --- gt-g-: 1 10: 1 I 5: 1 1: 1 0.5: 1 0.2: 1 0.1: 1 1134551 Table1 (fresh sand, Table2 0.2 T1.9 12.3 1.0 15.8 18.1 6.7 12.1 5.0 J7.0 riO, o | l5,, 0

Indicator

Residual content of vever in water, mg / l, after 0 min of settling W) and water treatment

Table 4

Dose of flocta nta, mg / l 0.3 1 0.5 I 0.7 Tl, 0 I 1.5 I 2.0

Claims (3)

1. METHOD FOR LIGHTING LOW-MOID WATER, including the introduction of a mineral opacifier, aluminum sulfate and flocculant followed by settling, characterized in that, in order to increase the degree of clarification and reduce the duration of the process, a mixture of filter perlite and crushed silica sand is used as a mineral opacifier, taken in a ratio of 2: 1 to 1: 1. 2. The method according to p. ^ Characterized in that the opacifier is introduced in an amount of 7-10 g / l. 3. The method according to p. 1, characterized in that after sedimentation, the sediment is stirred up. IWTFTiS 1130551