CS254685B1 - A method of industrial waste water treatment - Google Patents

Abstract

The invention relates to a method of purifying industrial wastewater in the presence of inorganic coagulants, in which montmorillonite and a condensation product of an organic acid with a polyamine are added to the wastewater. The method can be used mainly for purifying textile wastewater, where the water is strongly colored and contains petroleum substances. It can also be used for purifying other wastewater.

Description

The invention relates to a method of treating wastewater by flocculation, by which it is possible to increase the efficiency of treating wastewater while simultaneously improving the sedimentation rate of sludge and reducing the content of oil substances.

Currently, most industrial waters are treated by coagulation (mainly textile wastewater), with organic flocculants usually used to intensify the process.

Under French patent 2,379,306, in addition to an inorganic coagulant (aluminum sulfate), a nonionic surfactant with diamine is added to the wastewater.

Under UK Patent 1,572,396, wastewater is treated by adding an inorganic coagulant and an organic flocculant with a molecular weight above 500,000.

Pursuant to the USSR patent 835 967, wastewater from dyeing is treated by adding inorganic. coagulant in the presence of an organic flocculant.

Under Austrian patent 288,981, drinking and waste water are purified using sodium montmorillonite and a high molecular weight flocculant, with the high molecular weight flocculant being added to the mixing tank last.

The disadvantage of the current state of industrial wastewater treatment with inorganic coagulants is insufficient cleaning efficiency, long sedimentation time, and insufficient efficiency of removing oil substances.

In the cited patents, the organic flocculant performs the function of accelerating the sedimentation of the inorganic coagulant flocs.

The above and other disadvantages are solved by the present invention, according to which 10 to 500 mg. dm ^-3 of mortmorillonite and 0.2 to 20 mg. dm ³ of the condensation product of stearic acid with diethylene-3-amine, or 0.2 to 20 mg. dm ^-3 of quarto are added to the wastewater in the presence of inorganic coagulants.

Before cleaning

COD _cr (mg. dm ^-3 ] a

597.0 b c

Sludge volume in 30 min. sedimentation in "b" and "c" is lower, compared to "a" by approx. 10%. Example 2

For 1 dm ³ of industrial textile wastewater, the optimal doses of coagulants, minerals and organic matter were determined and added as follows:

a] — 600 mg FeSO₃. 7 H2O + 320 mg CaO of the reaction product of stearic acid with diethyleneamine.

The advantage of the purification method according to the invention is the increase in the efficiency of purification of industrial waters compared to purification with inorganic coagulants, or their combination with an organic flocculant. The advantage of the purification method according to the invention is the acceleration of sludge sedimentation, improvement of sludge drainage capacity and improvement of oil removal.

The organic substance added to montmorillonite does not have flocculation ability and acceleration of sedimentation by itself; the improvement of sludge dewatering ability occurs after its reaction with Na montmorillonite.

The invention is further illustrated, but not limited, by the following examples:

Example 1

For 1 dm ³ of industrial textile wastewater, the optimal doses of coagulants, minerals and organic matter were determined and added as follows:

a) — clarification with 400 mg FeSO₃. 7 H2O and 200 mg CaO

b) — clarification with 400 mg FeSO-i. 7 H2O and 200 mg CaO + 100 mg Na montmorillonite + + 2.5 mg condensation product of stearic acid with diethylene-3-amine

c) — clarification with 400 mg FeSO4.7 H2O and 200 mg CaO + 100 mg Na montmorillonite + + 0.5 mg polyacrylamide (Praestol 522 K]

After Cleaning

COD _gr (mg. ^dm3 ) %

298.5 50.0 268.6 55.0 278.5 53.3 b)

— 600 mg FeSO₃.7 H2O + 320 mg CaO + +100 mg Na montmorillonite + 2.5 mg quaternized product of stearic acid with diethylamine

c) — 600 mg FeSO4.7 H2O + 320 mg CaO + + 0.2 mg polyacrylamide (Praestol 522 K]

After cleaning

COD _cr (mg . dm ^-3 ) % Oils % (mg. dm ³ )

Cleaning efficiency:

Before purification COD _cr (mg. dm ^-3 )

691.2 and 326.4 52.8 6.70 i59.7 Petroleum substances b 268.8 61.1 3.14 81.1 16.63 c 307.2 55.6 3.81 77.1

The volume of sludge in 30 min. sedimentation in "b" and "c" is lower, compared to "a" by about 7%, the sludge dewaterability in "c" improved by 12%, in "b" by 9%, compared to "a".

Claims (1)

2 5 4 8 8 5 Cleaning efficiency: Before cleaning CHSKcr (mg. Dm-3) After cleaning CHSKcr (mg. Dm-3)% Petroleum% (mg. Dur3) 691.2 and 326.4 52.8 6.70 i59.7 Petroleum substances b 268.8 61.1 3.14 81.1 16.63 c 307.2 55.6 3.81 77.1 Sludge volume in 30 min. sedimentary in "b" and "c" is lower, compared to "and" 0 "of about 7 ° / o, improved sludge drainability in" c "of 12%, in" b "of 9 ° / o, versus" a " “. FREDMET A process for the purification of industrial waste water in the presence of inorganic coagulants, characterized in that 10 - 500 mg is added to the waste water together with the inorganic coagulant. dm-3 In the invention, morillonite and 0.2 to 20 mg. dm "3 condensation product of stearic acid with di-ethylene-3-amine, or 0.2 to 20 mg dm" of a 3-quaternization product of stearic acid with diethylamine.