SU1535836A1 - Method of removing triphenylmethane dyes from waste water - Google Patents

Abstract

The invention relates to methods of treating wastewater from triphenylmethane dyes and can be used in the chemical industry. The aim of the invention is to increase the purity without increasing the consumption of alkaline reagent. The method is carried out by treating wastewater with sodium hydroxide in an amount of 3 to 60 kg / m ³ in the presence of a porous carbon sorbent in the amount of 10 to 80 kg / m ³ . The method provides the possibility of achieving a degree of purification of 99.9% with the consumption of reagents significantly lower (4 times) than in the known method. 6 tab.

Description

The invention relates to methods for treating wastewater from the production of triphenylmethane dyes and can be used in the chemical industry to solve the problem of disposing of large tonnage waste generated from the reagent treatment of wastewater from the production of triphenylmethane dyes.

The purpose of the invention is to increase the degree of wastewater treatment without increasing the consumption of alkaline agent.

PRI me R s 1-4 (comparative). The original wastewater is the production of triphenylmethane dyes for acid blue O, acidic green, basic bright green, basic blue K.

Calcium peroxide is added to 1 m of wastewater produced by an individual dye in an amount of 5% by weight of the dye contained in the wastewater, the pH is set to about 6 and held for 10 hours. Similar operations are carried out with all wastewater. The content of the dye before and after cleaning is determined by a calibration graph, measuring the optical density of the waste water at the corresponding wavelengths.

Data on the effectiveness are given in table. one.

Examples 5-8. The original wastewater is a mixture of wastewater from the production of triphenylmethane dyes of the main bright green, acidic green, acid blue O. The optical density of the mixture at 200-fold dilution is 0.32 at a wavelength of 620 nm.

With stirring, 6 kg of caustic soda, in the form of a 42% aqueous solution, are added to 1 m5 of wastewater mixture, stirred for 60 minutes. A sticky unfiltered precipitate forms (Example 5). Have an eye§

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scoop water is measured by absorbance at a wavelength of 620 nm. The following examples (6-8) are carried out analogously to example 5, but prior to the addition of caustic soda, 10 to 50 kg of sorbent underburning are introduced with stirring, as a result of which the degree of purification increases and a loose, easily filtered sediment forms.) 0

The degree of sewage treatment is given in table. 2

Examples 9-13. The original wastewater is similar to examples 5-8.

To 1 m3 of wastewater mixture, 15 kg of sorbent is added, with stirring, not burned, then 3 to 12 kg of caustic soda in the form of a 42% aqueous solution, contacting is carried out for 60 minutes, the precipitate is separated by settling or by filtration.

The degree of sewage treatment is given in table. 3

Examples 14-15. The original wastewater is a 25-color primary dye green production mother liquor. The optical density at a dilution of 12,500 times at a wavelength of 590 nm is 0.38, and the content of the colored substance is 88.3 g / l. To 1 m of waste water, 36-48 kg of sodium hydroxide are added in the form of 42% - sticky unfilterable precipitate is formed.

Examples 16-17. The original wastewater is similar to examples 14-15.

With 1m3 of waste water, 40-80 kg of sorbent is added, under ignited, and 36-48 kg of sodium hydroxide in the form of a 42% aqueous solution. A well-filtered precipitate forms, easily discharged from the apparatus.

The cleaning results in examples 14-17 are given in table. four.

Examples 18-19. The original wastewater - the mother liquor of the production of the main blue dye. The optical density of the wastewater at a dilution of 62500 at a wavelength of 50,590 nm is 0.255; dye content 45.6 g / l.

With stirring, 48-60 kg of sodium hydroxide in the form of a 42% aqueous solution are added to 1 m3 of waste water, and then filtered off.

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Examples 20-21. The original wastewater is similar to Examples 18-19.

With stirring, 48-60 kg of sodium hydroxide in the form of a 42% aqueous solution are added to 1 m3 of waste water, then filtered. - When adding a sorbent - active carbon, the degree of purification increases, the precipitate is well filtered.

The cleaning results for examples 18-21 are given in table. five.

Below are data on the consumption of reagents to achieve a purity of 99.9% according to the invention (caustic soda 1 + sorbent) and the prototype (calcium peroxide) in the purification of waste water produced by the main bright green.

Reagent Consumption, kg / m Caustic soda 48

Sorbent80

Calcium peroxide 440

Thus, when using the proposed method, it is possible to increase the degree of wastewater treatment up to 99.9% without increasing the consumption of the alkaline agent; the efficiency of the purification process is increased due to the use of cheaper and more accessible reagents (caustic soda and carbon sorbent, prototype calcium peroxide), as well as the possibility of using production waste as a carbon sorbent; the wastewater treatment technology is simplified by filtering the precipitate; the amount of sludge produced is reduced and their utilization is simplified (burning of the spent sorbent with organic impurities in utilization boilers to produce heat).

Claims (1)

Invention Formula The method of purification of wastewater from triphenylmethane dyes, including treatment with an alkaline reagent and separating sludge, is different from the carbon sorbent in the amount of 10-80 kg / m. Table 1 About 10 30 50 14 rier 18 19 20 21 Amount of sobena- Amount of caustic active carbon, kg / h3 soda, kg / m3 ABOUT ABOUT ten 60 48 60 48 60 Table 2 Sticky, unfiltered Loose, easily filtered it m Table3 TableA 36 65.1 Sticky, unfiltered Table3 whom Degree of cleaning% 54.2 96.9 99.8 99.9