SU789435A1 - Method of waste water purification in felt production - Google Patents

Description

(54) METHOD FOR CLEANING WASTE WATER

The invention relates to methods for cleaning wastewater shaft of felt production and can be used to clean similar wastewater, i.e. sulfuric acid, dye, surfactant, oil, soap, grease, suspended substances containing a large amount fiber. The known methods of sewage treatment make it possible to purify not all of the mixed effluent, but only its individual components. The known method of wastewater purification from dyes in the presence of surfactants by flotation in an acidic medium (pH 4) l The closest to the proposed technical result and the achieved result is a method according to which the waste water is subjected to a preliminary degreasing mixture consisting of calcium chloride, magnesium chloride and magnesium sulfate, taken in a ratio of 3: 1: 1. Biological cleaning is not required. After degreasing, the water is coagulated with aluminum sulphate and an alkaline precipitate is introduced from the second purification stage, the pH 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 12-12.2. Purified water is neutralized with carbon dioxide to pH 7.5-8.2 and used in circulation. The degree of purification of CB in CPX is 86.8% in suspended matter - 40%, and in fatty substances - 65% 2. The disadvantages of the known methods are insufficient purification in suspended and fatty substances, as well as the impossibility of simultaneous purification from the rest, contaminating components taking into account the interaction of all factors of a heterogeneous system. The purpose of the invention is to clean the effluent from dye, surfactants, oil, soap, grease, suspended solids, fibers when they are present together and the degree of purification increases. This goal is achieved by the fact that the waste water is averaged, saturated with chlorine, electrocoagulated in an acidic medium, neutralized with lime to p. followed by pressure flotation. The method is carried out as follows. Wastewater from flax-felt production shaft (, 5, dye concentration 107 mg / l, fiber 215 mg / l, suspended matter 200 mg / l, oil and soap 60 mg / l, fat 76 mg / l, sulfuric acid 778 mg / l) enter the concentration and consumption averager calculated for the flow to stay for 8-12 hours. After averaging, the iodine waste enters the saturation chamber with chlorine, where 90-100 mg of chlorine is supplied to destroy the dye / which simultaneously leads to additional acidification of the runoff to, 2 and contributes to the effective bleaching of electrocoagu on the stages ltsii. Contact time with chlorine 10 min. From the chamber, the water enters the suction chamber, from where water is taken by the pump while simultaneously supplying 2-3% of air to the suction inlet of the pump and is fed into the electrocoagulant flotation cell (first flotation stage) for 30 minutes. Flotation is eliminated by saturation with air and bubbles of electric gas. For electrocoagulation, steel (iron) anodes are used, connected in a monopolar circuit, connected via a rectifier. At this stage of purification, the dye, oil, lvlo, grease, suspended substances, fibers, surfactants are well removed, the COD is reduced.

After electrocoagulation-flotation, water enters to neutralize with lime with automatic regulation of its dose by pH meter within. Neutralization chamber is designed for a 15-minute stock stay. The indicated pH limits are aimed at the rapid and complete transfer of iron ions remaining in the solution after electro-coagulation in an acidic medium to iron hydroxide, followed by its discharge by pressure flotation together with sorbed dye residues. .

The neutralized effluent from the neutralization chamber is taken up by a pump, to the suction inlet of which 3% air is fed, and through the pressure tank ,. calculated for a two-minute stay of water, enters the pressure flotation chamber with a process time of 30 minutes (second flotation stage).

After the second flotation stage, a decrease in all indicators of contamination is lower than the MPC values for

industrial wastewater discharged into the city sewer. The table shows the results of wastewater treatment.

The sludge and sediment with 95% moisture, formed in the electrocoagulator-floater, neutralizer and pressure floater, is collected in a sediment collector and from where it is removed or fed to mechanical dehydration (for example, using centrifuges or vacuum filters).

From the pressure flotation cell, the purified water can be lowered into the city sewage system or used in circulation in the enterprise.

The proposed wastewater treatment method of a flax-felt production shaft allows maximum extraction of fat, 0 oils, suspended substances, fibers, detergents, for which two flotation stages are used, as well as dye destruction due to chlorination with large doses of chlorine and electrocoagulation in 5 acidic media. .

57894356

The proposed method provides control with post neutralization.

a reduction in the content of synthetic surfactants by 85-90%, characterized in that

and high effect (97-98%). Delays in order to increase the degree of cleansing

fat, oil, suspended solids, grease and suspended solids with a possible lock. The dye is removed by 95-98% by the simultaneous purging of the edge. These data are significantly superior to the fillers, fibers, oils, and synthetic methods by a known method. surfactants

The use of the proposed wastewater after averaging the billet considerably increases the effect of purifying chlorine, subjecting electrocoagulous wastewater to a shaft of flax felt in acidic medium, neutralizing production, as well as enterprises with an ante-stream with subsequent pressure flotation composition of wastewater. tie.

water, which, in turn, is prevented. "

em pollution of the water basin. The method according to claim 1, characterized by the introduction of this method and the fact that the neutralization

In case of wastewater treatment, the flax shaft is conducted to a pH of 8-9. Felt production expected 15 Sources of information, the economic effect will be about taken into account in the examination of 35 thousand rubles. USSR author's certificate

1 ,, Plf inventions 2. USSR author's certificate

1. The method of wastewater treatment No. 431223, cl. from 02 C 5/02, 24 07 72

shaft flax-felt production coa-20 (prototype). and /./

 379541, cl. C 02 C 5/06, 09.02 71

Claims (2)

Claim 1. A method of treating wastewater of a felt and felt production by co-20 walks with subsequent neutralization, characterized in that, in order to increase the degree of purification from fat and suspended solids with the possibility of simultaneous purification from dyes, fiber, oil and synthetic surfactants, wastewater after averaging is poured with chlorine, subjected to electrocoagulation in an acidic environment, neutralized with lime, followed by pressure flotation. 2. The method of pop. 1, characterized in that the neutralization is carried out to a pH of 8-9.