SU1039898A1 - Method for treating effluents from ion-exchange desalination plants - Google Patents

Abstract

I. METHOD FOR TREATING WASTE. ION-EXCHANGE SALTING SYSTEMS, which includes the mixing of acid and alkaline wastewater, flue gas treatment and sludge separation, characterized in that, in order to reduce the hardness and salinity of the treated wastewater, 13 ... miQTKif divide the janse into two parts the more mineralized part of the acidic wastewater is mixed with alkaline calcium carbonate slurry, passed through a layer of calcium sulfate and separated from the sediment, and then mixed with another part of the acidic wastewater and treated with part of the slit wastewater before precipitation of magnesium oxide with subsequent separation of it, and the second part of alkaline wastewater is treated with flue gases before conversion of hyarate alkalinity to carbonate and mixed with neutralized wastewater, the mixture is passed through a layer of calcium carbonate, and the resulting alkaline slurry of calcium carbonate is mixed g is watered with a portion of acidic water in 2. The method according to claim L, characterized in that 30-5% of acidic wastewater is mixed with alkaline isham, and 30-60% of alkaline wastewater is used to precipitate magnesium hydroxide.

Description

The invention relates to methods for the regu- lar treatment of w.HZh dam water and can be used to demineralize regeneration wastewater from hydrogen – cation and anion – filter filter of desalting plant. A known method of purification of wastewater from hardness salts, including separation of streams, treatment of one of them with lime, mixing of streams and separation of hydroxy magnesium oxide, subsequent treatment of water and separation of calcium carbonate residue in a vortex reactor i. The disadvantage of this method is the increased consumption of scarce reagents, which increases the cost of water treatment. The most brighter to the isofotech by its tonic essence is the method of sewage treatment, including neutralization of acidic wastewater of ion-exchange desalting plants with alkaline regeneration solutions and subsequent formation of flue gases and separation of sediment 2. The disadvantages of this method are no stiffness and salinity of clean sewage. The aim of this is to reduce the treated hardness and salinity of wastewater. The chain is reached by acidic and alkaline wastewater being divided into two parts, the more mineralized part of acidic wastewater is mixed with alkaline calcium carbonate sludge and passed through a layer of calcium sulfate and separated from the sediment, and then mixed, with another part of acidic wastewater, and treated with part of alkaline wastewater until precipitation of devi magnesium hydroxide followed by its separation, and the second part of alkaline wastewater about It is processed with flue / gases before the conversion of hydrated alkali into carbonate and mixed with non-sewage, the mixture is passed through a calcium carbonate junction, and the resulting alkaline calcium carbonate sludge is mixed with a portion of acidic water. Preferably, an alkaline sludge is mixed with an SO-5O% acidic wastewater, and 30-6O% alkaline wastewater is used to precipitate magnesium hydroxide. The drawing shows the scheme obra, waste sewage ion-exchange desalting plants. The method is carried out as follows. In the process of regeneration and washing of hydrogen-catalytic filters 1, a more mineralized part of acidic wastewater is separated and fed to apparatus 2, where it is mixed with alkaline sludge of calcium carbonate, passed through a layer of calcium sulfate and separated from the precipitate. The clarified water is supplied to the apparatus 3, where it is mixed with another part of the acidic wastewater, which is fed through the 4- Shellovyvny pipeline, which is formed during the regeneration and washing of the anionite filters 5, is also divided into two parts. One part of this water is treated with acidic wastewater until the precipitation of magnesium hydroxide and its subsequent separation. The second part of the alkaline wastewater is treated with flue gases in apparatus 6 before transferring hydrated alkalinity to carbonate and fed to apparatus 7, where it is mixed with clarified water from apparatus 3, passed through a layer of calcium carbonate and sent through pipeline 8 to the consumer. The alkaline sludge obtained is fed through conduit 9 into apparatus 2, and its excess amount is discharged through a pipe 10. The suspension of calcium sulphate and magnesium hydroxide is removed accordingly. Consequently, pipelines II and 12. The table (columns I and 2) shows the compositions and the number of regeneration ones. waste water of the ordr-ation and anion-exchange filters of the desalting plant when used for the regeneration of sulfuric acid and caustic soda. In the process of regeneration, acidic waste waters are separated (column 3 by increased mineralization, column 4 is the rest). The more mineralized part of the acidic wastewater is mixed with 37.5-4 O kg of calcium carbonate in the form of alkaline sludge. In this case, the acid is neutralized and the calcium content increases to 135,142 mg-eq / l, which is much higher than the solubility of calcium dehydrate calcium sulfate under these conditions. As a result, 79.5 kg / h of the latter is crystallized in the calcium sulphate layer. The average composition of the water after separation of the sediment is shown in column 5. Water is mixed with another part of acidic wastewater and 33.5 m / h of alkaline acidic BOiJM; o average alkalinity of 80.3 mg-aq / l. As a result, 13 kg / h of magnesium hydroxide is formed, which is separated from the water. The clarified water is mixed with the remaining

3Sh398984

26, S m / h of alkaline C5 waste water, recycling the same wastewater after treatment

flue gases before conversion to a known method, alkalinity alkalinity in carbonate, and

the mixture is passed through a layer of carbonate. Comparison of the test data is shown. As a result, 5 grams are harvested, which has been proposed using 46, 9 kg / h of calcium carbonate. The composition of this method is that the stiffness of treated wastewater is welcome in column 6, the average water decreases by an average of 1 °

and in column 7, for comparison, it is given co-times, and the salt content is 16%,

 Calcium 28.00,05 48.11 11.70, OZ 18.5 Magnesium Sodium 9O, 48.8

Hydrogen

, 74.0 117,926.5 168.7 Sulfates

Chlorades

0.3 Alkalinity Dry residue, g / l

Water consumption, m / h

4O

93.6 69.1

3.00.3 .0.3 O, 3 1.9 1.9

61, O

 0.2 1.3 1.0 4.5 9.8

in 832 8100 SO 23 23.2 O, 8 9.7 10 18.5 0.2 0.2 3.4 8.8 55.8 55.8 1O5.2 53 53.6 62.8 5.9 3 , 7 4, O 4,6

Claims (2)

1. WASTE TREATMENT METHOD. ION-EXCHANGE DEMALTIFICATION PLANTS, including mixing acidic and alkaline wastewater, flue gas treatment and separation of sludge, characterized in that, with a chain for reducing the hardness and salt content of the treated wastewater, acidic and alkaline wastewaters are divided into two parts, each more mineralized part of acidic wastewater is mixed with an alkaline slurry of calcium carbonate, passed through a layer of calcium sulfate and separated from the precipitate, and then mixed with another part of acidic wastewater and treated with a part of alkaline wastewater before magnesium hydroxide is precipitated, followed by its separation, and the second part of the alkaline wastewater is treated with flue gases until the hydrated alkalinity is converted to carbonate and mixed with neutralized wastewater, the mixture is passed through a layer of calcium carbonate, and the obtained alkaline sludge of calcium carbonate is mixed with a part of acidic water. 2. The method according to π. 1, distinguished by the fact that 30-50% acidic wastewater is mixed with alkaline sludge, and 30-60% alkaline wastewater is used to precipitate magnesium hydroxide. o ζ © x> ζ © X