SU835967A1 - Method of waste water purification from dyes - Google Patents

Description

(54) METHOD FOR CLEANING WASTE WATER FROM DYES

({by reagents and sediment removal.

The aim of the invention is to increase the degree of purification.

This goal is achieved when using calcium hydrosulfoaluminate as a coagulant (in a three-sulphate form), and sewage with bio-flocculating properties at a pH of 9: O-9.8, preferably 1: 2.5, as a flocculating additive. - 1: 4.

The method is carried out as follows.

Calcium hydrosulfoaluminate (in a three-sulphate form in a volume of 4ОО-1OO ml, a solution formed as a result of extraction of diluted alunite (YES), annealed at 6OO-8OO b, in mg / l with calcium oxide hydrate in the amount of ZOO-375 mg / l.

After mixing, waste water with a biofloculating ability is added in a ratio of 1: 2.5-4 (e.g., which has undergone biological treatment in contact ponds or waste water after boiling cocoons) at pH 8.

Adding wastewater with a biofloculatory ability to ochstelaya in a ratio of 1: 2 or 1: 5 does not increase the cleaning efficiency, a pH of less than 9.0 reduces, and more than 9.8 does not change the effect of cleaning.

f

The discoloration process consists in the formation, coarsening and precipitation of colloidal particles as a result of the interaction of dyes with calcium hydrosulfonic aluminum in the trisulfate form in the presence of a biofloculating additive in a silk medium. Lightening occurs during ZO-6O min.

Comparative data indicating the optimality of the selected intervals of the ratios of treated water, wastewater with biofloculating capacity and pH are presented in the table.

Example 1. In a 25O ml cylinder, SOO ml of dye production (pH 7.0) with an optical density of 1.45 is injected, After calcium and 16.6 g of calcium sulfo aluminate in a trisulfate form (with concentrates with DA 2OO mg per liter and calcium oxide hydrate 375 mg / p) at a pH of 9.8 are added to 25 ml of waste water after boiling KoKOHOB (irfI 7.2; COD HU suspended substances 45 mg / l, dry

residue 1O44 mg / l). After transformation, rapid flocculation and coagulation of the suspension take place. The maximum bleaching of the solution occurs after 30 minutes and reaches the value of the optical density O, OZ. The color intensity of the treated wastewater is reduced by 98%, the COD by 81.7%.

PRI mme R 2. Experience is carried out analogously to example t, but 4.0 ml of calcium phosphate calcium aluminate in a three-sulfate form with a DA concentration of 60 mg / l and calcium hydroxide concentration of MOO / l, and then at pH 9, are introduced 0 add 40 ml of waste water after boiling cocoons; Intensity

coloring during the cleaning process is reduced by 9.3%, COD - by 67.9%.

PRI me R 3. Experience lead similarly to examples I and 2, and as a biofloculating additives take 25 ml of pond water (pH 6.9, COD 12O136 mgOd / l, weighted 156 mg / l, dry residue 40 mg / l ). The color intensity during the cleaning process is reduced by 97.3%, COD by 74.2% ..

Thus, the proposed method in comparison with the known increases the effect of purification from the introduction of calcium hydrosulfoaluminate in a three-sulphate form and a biofloculating additive with

47-85% to 87.8-98.0%; reduces the content in the purified liquid by reducing the concentration of reagents injected; reduces the volume of sediment compared to the sediment formed

aluminum hydroxide; Cheaper cleaning costs due to lower reagent costs.

Claims (3)

1.Mettiand TextitteMchitf 53, No. 2, 1972, 23O. 2. Text.cfieni. and CoEor 8, No. 7, 1976, 18-22. 3.Koiau, PoEeut. c6ntt i Ji5, io. No. 4, 186-196. H.Chimy; 5J62; 1976 (prototype).