RU2443635C1 - Method of purifying waste water from production of emulsion rubber and latex from leukanol - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: to implement the method, waste water from production of emulsion rubber and latex from leukanol is purified by adding a coagulant based on a polymer salt of a quaternary ammonium salt. The coagulant used is polydiallyldimethylammonium chloride in amount of 5-10 mg/l of waste water. The polydiallyldimethylammonium chloride is added to waste water before the floatation installation.

EFFECT: more than three-fold reduction of concentration of leukanol in the purified water after the floatation installation, which reduces water consumption for dilution to the leukanol discharge standard by more than three-fold.

2 cl, 2 tbl, 12 ex

Description

The invention relates to wastewater treatment for the production of emulsion rubbers and latexes from biodegradable leucanol and can be used in the industry of emulsion synthetic rubbers and latexes.

Currently, in the production of all emulsion polymerization rubbers, leucanol is used, which is the sodium salt of the condensation product of β-naphthalene-sulfonic acid with formaldehyde. Leukanol is well soluble in water, but practically does not undergo biological degradation (P. A. Kirpichnikov et al. Chemistry and technology of synthetic rubber. Leningrad, Chemistry, 1987). As a result of this, it passes through a system of treatment facilities in transit and enters natural water bodies.

Leucanol has high toxicity, impairs the organoleptic properties of water and the sanitary regime of water bodies, complicates the treatment of wastewater and is very stable with respect to the processes of natural self-cleaning of water bodies. The permissible leucanol content in wastewater before being discharged into a pond is achieved by simply diluting the wastewater (Collection N.N. Wastewater produced by SK. Central Black Earth Publishing House, Voronezh, 1969).

A known method of wastewater treatment for the production of emulsion rubbers and latexes from uncoagulated latex and polymer particles by adding a coagulant containing CaO-MgO (RF patent No. 2204531, MPK C08F 1/52, publ. 05.20.2003). However, this method does not allow purification of wastewater from leucanol and leads to additional salinization of water bodies.

A known method of treating wastewater containing hardly decomposable harmful substances by adding a coagulant or adsorbent to wastewater, separating solid products containing hardly decomposable harmful substances and liquids, decomposing a hardly decomposable harmful substance isolated with a solid product, peroxide (RF patent No. 2326056, IPC C02F 1/52, C02F 1/28, C02F 1/72, publ. 06/10/2008). However, the coagulant, consisting of polyacrylic acid, polyacrylamide resin, sulfates or chlorides of iron, chloride or polyaluminium chloride, has a multicomponent composition, which is inconvenient for use, and also ineffective for binding leucanol.

It is known to use polydiallyldimethylammonium chloride for the purification of drinking water (Guidelines MU 2.1.4.1060-01 approved by the chief state sanitary doctor of the Russian Federation on July 18, 2001).

The use of polydiallyldimethylammonium chloride for wastewater treatment in the production of emulsion rubbers and latexes from leucanol is not described in the literature.

The closest in technical essence and the achieved result is a method of purification of washing and wastewater production of latexes and polymers obtained by emulsion polymerization, the introduction of a coagulant based on a protein component containing, as additional ingredients, carboxylmethyl cellulose, urea, ά and β-amylase, fatty amine compounds , urea-formaldehyde resin and formalin. As amino compounds, alkylbenzylammonium chlorides can be used. This method allows you to bind leukanol, but it is difficult to apply in production, because the coagulant used has a complex composition and a multi-stage preparation method (RF patent No. 2281293, IPC С08С 1/15, C08C 2/06, C02F 1/56, publ. 10.08.2006).

Currently, the concentration of leucanol in the washing and wastewater production of emulsion rubbers and latexes ranges from 2.5 to 5.5 mg / L. After the flotation stage in wastewater treatment plants, from 1.25 to 2.9 mg / l.

An object of the invention is to reduce the concentration of the biodegradable dispersant of leucanol in the wastewater of the rubbers produced by emulsion polymerization discharged to treatment facilities, and to save water used to dilute the wastewater before being discharged into fisheries.

The problem is solved by adding emulsion polymerization to the wastewater of the rubber production workshop before dumping polydiallyldimethylammonium chloride (VPK-402) in the amount of 5-10 mg / l of wastewater into the general wastewater.

VPK-402 polyelectrolyte (TU 6-05-2009-238 86, amendment 1) is well soluble in water, in solutions of acids and alkalis. The empirical formula of the cell is: C ₈ H ₁₆ NCl.

The technical result is demonstrated by examples of specific performance.

Example 1. In the collector of chemical-polluted sewage production of emulsion rubbers and latexes in wastewater containing 2.5 mg / l of leucanol, polydiallyldimethylammonium chloride is added over 3 hours, maintaining a concentration of VPK-402 in wastewater of 5 mg / l. Samples of purified water are taken after flotation installation and the concentration of leucanol is determined. The concentration of leucanol is 0.33 mg / L.

The concentration of leucanol in wastewater is determined by the method PND F 14.1.15-95. Quantitative chemical analysis of water. The methodology for measuring the mass concentration of anionic surfactants in wastewater samples by the extraction-photometric method. M., 1995

Examples 2-6 according to the invention are made analogously to example 1 only with different concentrations of VPK-402 and are presented in table 1.

Control examples 7-12 (without the addition of VPK-402), when the content of leucanol is determined in the waste water from the production of emulsion rubbers and latexes before being discharged into the factory wastewater, and then the content of leucanol after flotation is determined, are shown in table 2.

It can be seen from the above examples that when wastewater is mixed in the production of emulsion rubbers and latexes with factory effluents, the concentration of leucanol decreases by a factor of 2-2.5 due to dilution of the latter.

The process of interaction of leucanol with VPK-402 should be carried out on more concentrated effluents. Therefore, the VPK-402 dosing site for wastewater was chosen as a collector of chemically contaminated sewage in the workshop for the isolation of rubber from latex for the production of emulsion rubbers and latexes (the main source of leucanol entering the enterprise’s wastewater).

The optimal content of VPK-402 in wastewater is 5-10 mg / l. The addition of VPK-402 less than 5 mg / l does not lead to the desired result, and an increase in the concentration of VPK-402 more than 10 mg / l is impractical because may lead to overstatement of the MPC of polydimethylammonium chloride in treated wastewater.

The data presented in tables 1 and 2 show that the addition of VPK-402 to the wastewater of the emulsion polymerization rubber production workshops before being discharged into the general wastewater by the present method reduces the concentration of leucanol in wastewater after flotation is installed by more than 3 times, which will accordingly allow reduce the flow rate of water used for dilution to bring the norms of leucanol discharge (MPC-11 mg / l), also more than 3 times.

Claims (2)

1. A method for treating wastewater from the production of emulsion rubbers and latexes from leucanol by adding a coagulant based on a polymeric quaternary ammonium salt, characterized in that polydiallyldimethylammonium chloride is used as a coagulant in an amount of 5-10 mg / l of wastewater. 2. The method according to claim 1, characterized in that polydiallyldimethylammonium chloride is added to the wastewater before the flotation unit.