RU2258044C1 - Method of treating process waste waters containing dimethylacetamide and isobutyl alcohol - Google Patents

Abstract

FIELD: waste water treatment.

SUBSTANCE: initial waste water is mixed with chloroform to extract dimethylacetamide and isobutyl alcohol and, after settling-assisted separation from chloroform, resulting mixture is passed through activated carbon. Thus purified water is then reused in process. Activated carbon is regenerated by chloroform. Chloroform loaded with desorbed substance and chloroform extract are combined and distilled to give dimethylacetamide, isobutyl alcohol, and chloroform. Distilled-off chloroform is divided into two streams, the first one being returned to regenerate activated carbon and the other is mixed with initial waste water.

EFFECT: reduced expenses due to reduced compound of costly adsorbent without loss in waste water treatment efficiency and enabled low-waste technology.

2 cl, 1 dwg

Description

The invention relates to the treatment of industrial wastewater and can be used in the production of synthetic fibers for wastewater treatment containing dimethylacetamide (DMAA) and isobutyl alcohol (IVS).

A known method of processing wastewater containing DMAA and ischemic heart disease, including their biological treatment in aeration tanks (see Sat. New methods and facilities for wastewater and wastewater treatment. L., 1981, p. 86-92).

The disadvantage of this method is the inability to dispose of components contained in wastewater.

Closest to the proposed technical solution is a method of treating wastewater containing DMAA and IHD, including filtering wastewater through activated carbon to produce purified water, regenerating activated carbon with chloroform, distilling spent chloroform with desorbed substances to DMAA, IHD and chloroform, which is returned to regeneration activated carbon (see AS No. 1599312, class C 02 F 1/28, published on October 15, 1990).

The disadvantage of this method can be attributed to the high costs associated with significant costs of expensive adsorbent and its regeneration.

The present invention is aimed at improving the efficiency of the process by reducing the cost of an expensive adsorbent while maintaining the efficiency of wastewater treatment, return of purified water to the technology and providing low-waste technology.

To achieve the technical result, the initial wastewater is mixed to extract DMAA and ischemic heart disease from it, the resulting mixture is separated by settling on water and the chloroform extract, which is supplied for distillation, the water is filtered through activated carbon to obtain purified water, activated carbon is regenerated by chloroform to obtain spent chloroform with desorbed substances and its subsequent distillation to DMAA, IHD and chloroform, two streams of distilled chloroform are diverted and one stream is returned for regeneration activated carbon, and the second - by mixing with the waste water source.

The distillation of spent chloroform with desorbed substances of the chloroform extract is carried out jointly.

The drawing shows a diagram of the method.

The apparatus 1 for the extraction of DMAA and IHD from the initial wastewater with chloroform is connected by the outlet of the treated water to the adsorber unit 2, and by the output of the chloroform extract through the collecting tank 3 and desiccant 4 to the distillation column 5. The distillation column 5 is equipped with leads for DMAA, IHD and chloroform. Through the buffer tanks 6 and 7, the conclusions of the chloroform of the distillation column 5 are connected to the extraction apparatus 1 and the adsorber unit 2. The conclusions of the DMAA and IHD of the distillation column with a buffer capacity 8. The outlet of purified water from the adsorber unit 2 is connected to a mechanical filter 9. The distillation column 5 is equipped capacity of 10 for bottoms.

The method is as follows.

The initial wastewater is fed into the extraction apparatus 1, into which chloroform is also added in an amount of 20-30 l / m ^{3 of} purified water. The components are mixed, a mixture is obtained and separated by settling on a chloroform extract containing DMAA and MBS, and water. Next, the water is supplied for filtration through activated carbon to the block of adsorbers 2. The water purified in the adsorbers 2 undergoes additional purification in the mechanical filter 9 and is returned to production. Chloroform extract through collection tank 3 and desiccant 4 enters the distillation column 5, in which it is separated by distillation into DMAA, IHD, chloroform and bottoms. VAT residue is returned to the apparatus 1 for extraction or is removed as waste. The chloroform distilled from the distillation column 5 through the buffer tank 6 is returned with one stream to the extraction apparatus 1 and with the other stream through the buffer tank 7 to the adsorber unit 2 for activated carbon regeneration. Chloroform spent after regeneration of activated carbon with desorbed DMAA and IHD comes from the adsorber unit 2 to the collection tank 3 and from there together with the chloroform extract through the desiccant 4 is sent to the distillation apparatus 5. The DMAA and IHD extracted from the chloroform extract from the chloroform extract are either reused in production or sent to the warehouse.

Example. Waste water containing a total concentration of DMAA and IHD in an amount of 800 mg / l is mixed with chloroform supplied in an amount of 25 l / m ^{3 of} purified water. At the same time, at least 90% of the DMAA and IHD contained in the water is extracted with chloroform and transferred to the chloroform extract.

After separation of the chloroform extract and water by settling, the extract is sent for distillation with the release of dissolved DMAA and IHD from it. After rectification in chloroform, no more than 0.01-0.1% of DMAA and IHD remains, and purified chloroform is returned for reuse in apparatus 1 for extraction and in block adsorbers 2 for regeneration of the adsorbent.

The water separated from the chloroform extract by sedimentation, containing about 10% of the initial concentration of DMAA and IHD, is sent to sorption treatment, where the water is purified to a maximum concentration limit of 0.4 mg / L DMAA and 1.0 mg / L IHD.

Thus, due to the use of preliminary water purification by extraction with chloroform, in which about 90% of DMAA and IHD are extracted from water, the consumption of expensive adsorbent is reduced by 10 times.

The use of the same reagent for extraction of DMAA and IHD from water and for regeneration of the adsorbent significantly simplifies the technology of water purification, since the rectification of both streams is combined to extract DMAA and IHD from them. Low-waste technology - only bottoms remaining after distillation and spent sorbent in an amount of not more than 2 tons / year per spinning machine are waste.

Claims (2)

1. A method of treating wastewater containing dimethylacetamide and isobutyl alcohol, comprising filtering the treated water through activated carbon to obtain purified water and regenerating activated carbon with chloroform to produce spent chloroform with desorbed substances and its subsequent distillation into dimethylacetamide, isobutyl alcohol and chloroform, returning from chloroform for activated carbon regeneration, characterized in that the initial wastewater is pre-mixed with chloroform for ex TRAC from it dimethylacetamide and isobutyl alcohol, and the mixture is separated by settling in water and the chloroform extract and then supplying the water for filtering through activated carbon, and the chloroform extract - by distillation, an additional stream withdrawn distilled chloroform and return it to the initial mixing with the sewage water. 2. The method according to claim 1, characterized in that the distillation of spent chloroform with desorbed substances and chloroform extract is carried out jointly.