CS211675B1 - Method of water purification and finishing - Google Patents

Abstract

The invention addresses the purification and further purification of water using acidic waters waste from the production of ethylbenzene and containing an increased content of aluminum chloride. Wash water from the production of ethylbenzene with a content of 2 to 260 g of aluminum chloride per liter is added to the water, in an amount depending on the type of water to be purified, so that the isoelectric point is reached and the dispersed particles agglomerate. Achieving the isoelectric point is accelerated by adding agents that adjust the pH of the resulting solution in the range of 4.5 to 10.5, preferably 7.2. After the process is completed, the agglomerated dispersed particles are separated from the treated water by sedimentation or filtration.

Description

The invention relates to the use of acidic waters, which are produced in the production of ethylbenzene, and which contain an increased content of aluminum chloride for the purification or purification of waters, which contain, in addition to dissolved organic and inorganic substances, dispersed substances of organic and inorganic origin. Simultaneously with the removal of dispersed substances, the number of bacteria and viruses present in purified and refined water will be reduced.

In the production of ethylbenzene, aluminum chloride is generally used as the alkylation catalyst, which is converted into a so-called liquid complex, part of the liquid complex is converted into an alkylation product and must be removed before further processing. Usually, the liquid complex, both dissolved and dispersed, is removed from the alkylation product by washing with water.

In this wash, the liquid complex is decomposed and aluminum chloride or partially hydrolysed aluminum chloride (AlClgOH) is transferred to the wash water. When this wash water is recirculated to the ethylbenzene plant, the aluminum chloride content of the wash water to be drained increases so that the wash water to be drained contains from 2 to 260 g of aluminum chloride per liter.

Nowadays, this water goes to the sewerage system and, in addition to unwanted water warming, aluminum chloride is lost.

This disadvantage is overcome by the object of the invention, i.e. the method of purifying and finishing the water. The essence of the invention consists in adding to these waters washing water from the production of ethylbenzene containing 2 to 260 g of aluminum chloride per liter in an amount depending on the type of water treated until the isoelectric point is reached and the dispersed particles agglomerate. The attainment of the isoelectric point is accelerated by the addition of acids or bases in an amount depending on the type of water to be treated until the pH of the resulting solution is in the range of 4.0 to 10.5, preferably 7.2.

After completion of the process, the agglomerated dispersed particles are separated from the treated water by sedimentation or filtration.

The advantage of this process is that aluminum chloride is used to purify and purify the water, leaving the process as waste.

The method described is evident from the following examples:

He did

In urban waste water of the following composition:

COD (mg 0 ₂ / l) 138.2

BOD (mg 0 ₂ / l) 72.4 suspended matter (mg / l) 35.8 turbidity (relative%) 293.0

PO ^3- (mg / L) 1.1

Escherichia coli (number of organ./1) 5.10®

Para coli (number of organisms / L) 11.10 ® was added per 1 L of water to 80 mL of ethylbenzene wastewater containing 250 g AlCl 4 / L. The resulting pH of the mixture was 7.18. Immediately after the addition of ethylbenzene waste water, the resulting mixture was vigorously stirred for 5 minutes. For an additional 30 minutes, the water was stirred at a rate such that the Camp's number did not fall below 43,000 and did not exceed 64,000. After stirring, the water was subjected to simple sedimentation for 60 minutes.

The following values were found in the sedimented water:

COD (mg 0 ₂ / l) 23.3

BOD ₅ (mg 0 ₂ / l) 9.3 suspended matter (mg / l) 3.0 turbidity (relative%) 100.0

PO ^3- (mg / L) 0.22

Escherichia coli (number of organ./1) 0

Para coli (number of organisms / 1) 4.10 ³

Example 2

To influent wastewater in an amount of 700 m ³ / h by the composition described in Example 1, was continuously fed Wastewater from the production of ethylbenzene with an average 230 g of AlCl ^ / l 0.1 ^m3 / 1 m ³ wastewater. After mixing, the perikinetic and orthokinetic phases in the plant, the following average values were found in the effluent from the separation stage:

COD (mg O ₂ / l)

BODg (mg O ₂ / l) suspended substance (mg / 1) turbidity (relative%)

PO ^3- (mg / l)

Escherichia coli (number of organ./1) Para coli (number of organ./1)

18.2

7.6

2,0

68.0

2.10 ³

Example 3

-and

To water containing laundry detergents anionaktivníoh 450 g / m were added to the waste waters from the production of ethylbenzene in an amount of 0.2 m ^{3/1 m3} laundry waters. After intensive mixing of the phases of slow agitation and subsequent sedimentation, the content of anionic detergents in the sedimented water dropped to 54 g / m ³ .

Example 4

Into surface water of composition:

p-alkalinity (mval / 1) 0.12 m-alkalinity (mval / 1) 1.12 hardness total (mval / 1) 4.9 specific conductivity CuS / cm 713.0 color (Pt number) 48.0

COD (mg 0 ₂ / l) 6.28

BOD ₅ (mg 0 ₂ / l) 2.42 was dosed with ethylbenzene wastewater in an amount of 0.05 m / 1 m of surface water. After passing through the clarifier, this water exhibited the following composition:

m-alkalinity (mval / 1) 0.43 total hardness (mval / 1) 4.7 specific conductivity (S / om) 328.0 color (Pt number) 22.0

COD (mg O ₂ / l) 3.12

BSKg (mg O ₂ / l) 1.08

The invention can be applied in the treatment and purification of urban waste water, industrial waste water and in the treatment of surface water.

Claims (1)

SUBJECT OF THE INVENTION Process for the purification and finishing of waters containing dissolved and dispersed organic and inorganic substances, bacteria and viruses, characterized in that washing water from the production of ethylbenzene containing 2 to 260 g of aluminum chloride per liter of quantity is added according to the type of treated water isoelectric point and agglomeration of the dispersed particles, the reaching of the isoelectric point being accelerated by the addition of acids or bases in an amount according to the type of finalized water until the pH of the resulting solution is in the range of 4.0 to 10.5, preferably 7.2, and at the end of the process, the agglomerated dispersed particles are separated from the treated water by sedimentation or filtration.