SU431123A1 - METHOD OF CLEANING WASTE WATER1 - Google Patents

Description

The invention relates to the field of Wastewater treatment plants for the primary processing of wool, sheepskin and felted-felt industries.

A known method of sewage treatment is to treat them with aluminum sulphate and lime milk to a pI of 12.0-2.2. The precipitate formed after settling and separation is discharged into the slag collector, and the clarified water, after acidification with sulfuric acid to pH III, is discarded for biological purification. It is noted that the degree of purification according to XilK is 71.9-75.9%, the formation of 60% of sediment from the volume of wastewater, and further biological treatment of the discharged waters is necessary.

In the proposed method, the wastewater is preliminarily degreased with a mixture consisting of calcium chloride, magnesium chloride and magnesium sulfate, taken in a ratio of 3: 1: 1. This increases the degree of purification by COD to 86.8%, reduces the volume

reprocessable sludge up to 20% of the volume of wastewater and thereby eliminates further biological treatment of discharged water. And p and MER. 20 liters of wastewater after washing the wool are placed in a calibrated bottle and a mixture of magnesium chloride, calcium chloride and magnesium sulfate is added to it, taken in a ratio of 3: 1: 1 in an amount of 2.5 g / l. The mixture is stirred and subjected to 2 hours of settling. After settling, 1 l of fat emulsion sediment is separated.

In tab. 1 shows the results on the degreasing of runoff.

Table 1

The defatted water is treated with aluminum sulphate at the rate of 100 mg / l in terms of Alg (804) 3 and the alkaline residue is introduced from the second purification stage, while the pH of the water rises from 6.7-7 to 9-9.2 and the mass is settled. After settling and separating the precipitate, the purified water is treated with lime milk to a pH of 12.0-12.2. Cleaning Indicators

The precipitate after settling and delamination, as well as Purified water after acidification with carbon dioxide to pH 7.5-8.2, has been used in the circulating cycle.

In tab. 2 shows the results of experimental studies and comparative indicators of the known and proposed methods.

table 2

Subject image

The method of wastewater treatment by treating them with aluminum sulphate and lime milk to a pH of 12.0-12.2, followed by settling of the sludge and separation, characterized in that, in order to increase the degree of purification, as well as reduce the volume of the sludge being processed, the wastewater treatment with aluminum sulphate is subjected to degreasing with a mixture consisting of calcium chloride, magnesium chloride and magnesium sulphate, taken in accordance with 3: 1: 1.