SU1375566A1 - Method of treating effluents of sulfate pulp production - Google Patents

Abstract

The invention relates to wastewater treatment methods, can be used in flotation treatment of wastewaters containing sludge-lignin in the pulp and paper industry, for flotation extraction of valuable components in the mining, microbiological and chemical industries and allows for improved purification , increase flotation rate and reduce sediment moisture. Purification is carried out by introducing into the treated waters containing coagulant - aluminum sulfate flocculant of the polyacrylamide type and the flotation reagent - N- (2 -oxyethyl) oxazolidine oleic acid, followed by separation of the precipitate by flotation. Fluorine reagent is obtained by reacting N- (2 -oxyethyl) oxazolidine with oleic acid. The reaction proceeds with a short (0.5 h) heating of the mixture. When treating wastewater containing 4.3 g / l of sludge lignin and 18–20 mg / l of A12 (50) 3 (according to A1), by administering flocculant in the amount of 1 g / kg of dry sludge lignin (p. .-l.) and flotation reagent in the amount of 4-16 g / kg N.L. the degree of purification from suspended substances is 96%; the bleaching efficiency is 98%; the flotation rate constant is 1.66 -1 1 10 s. 2 tab. & (L

Description

ate

05

about:

The invention relates to wastewater treatment methods and can be used in flotation treatment of wastewaters containing sludge lignin in the pulp and paper industry, as well as for flotation extraction of valuable components in the mining, microbiological, and chemical industries.

The purpose of the invention is to increase the degree of purification, increase the flotation rate and decrease the moisture content of the sediment.

The method is carried out by introducing into the treated waters containing coagulant - aluminum sulphate, flocculant and flotation reagent with subsequent separation of the precipitate by flotation. N- (2-oxy diethyl) oxazolidine oleic acid is used as a flotation reagent.

CH,

/

N

C UNC

 CHjCHjOH

Flotation reagent receive interaction. Viyu of N- {2 -oxyethyl) oxazolidine with oleic acid. The reaction proceeds at a short (0.5 h) heating1 | mixes.

The reagent is a light yellow waxy substance, soluble in water and other organic solvents. Easily hydrolyzed in water, environmentally friendly.

Example 1. The synthesis of N- (2-oxyethyl) oxazolidine oleic acid is carried out as follows.

To 19.9 g (0.17 mol) of L- (2-hydroxyethyl) oxazolidine was added 28.2 g (0.1 mol) of oleic acid. The mixture is heated for 0.5 hours at 170 ° C, then cooled before and under vacuum (20 mmHg, degree). The excess of oxazolidine is distilled off. The residue in the bottom is crude N- (2 -oxyethyl) oxazazolidine oleic acid in the form of a viscous dark brown waxy substance, soluble in water, which is used for flotation in crude form. Yield: 39.8 g (99.6%). The product can be purified by recrystallization from ethanol. The pure product is a light yellow waxy substance with no defined melting point.

Found,%: C 69.24, 69.47; H 11.48, N 3.21, 3.35.

C.

C 69.13; H 11.35;

N

Calculated, 3.50.

The IR spectrum contains bands, cm: 1010, 1100, 1180 (vibrations of the oxazolidine cycle), 1640 (), 1590 (C00), 1680, 3350 (NH).

As wastewater, wastewater from the Baikal Pulp and Paper Combine containing sludgeon in the amount of 4.3 g / l and coagulant nt — aluminum sulfate 18-20 mg / l (APM) is investigated.

Para. And measure 2. To a sample of 500 ml of waste water, 1-4 ml of a 0.5% aqueous solution of N- (2 -oxyethyl) oxazolidine oleate acid are added. Sample ayut in, with a pressure of 0.2 MPa, mix for 2-5 minutes and feed into the flotation column simultaneously with flocculant. As flocculant, San-floe is used, which is similar in properties to polyacrylamides. The kinetics of the flotation process is estimated by the volume of compacted sludge-lignin or the volume of clarified water. The degree of purification from suspended substances is 96%, the effectiveness of reducing color in 98%, the constant of float growth rate 1, 66-10,

In tab. Table 1 presents data on the efficiency of the flotation process, depending on the dose of the flotation reagent at a pressure of 25 MPa and a dose of flocculant 1 g / kg of dry sludge lignin.

Table 1

Constant

In tab. 2 presents comparative data on the efficiency of the process.

cleaning known and proposed ways.

table 2

Continued table. 2

Indicators for the method

2 4-6

300 18

0.76 1.66

Purification efficiency from suspended substances,% 89.2 96.2

well-known proposed I

The efficiency of discoloration,% 90.2

Humidity photofluid,%

96-97

98.7 93-95

Claims (1)

Invention Formula A wastewater treatment method for sulphatecell production, including the introduction of coagulant, flocculant and flotation reagent followed by the separation of sediment by flotation, in order to increase the degree of purification, increase flotation rate and decrease moisture content of the precipitate; N- (2 -oxyethyl) oxazolidine is oleic acid is introduced as a flotation reagent.