RU2707023C1 - Method for reagent treatment of wastes from process equipment for production of industrial fabrics with impregnation from synthetic fibers - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to a method for reagent treatment of wastes from washing process equipment for production of industrial fabrics with impregnation from synthetic fibers contaminated with an impregnating solution containing harmful organic substances to be recycled. Method for reagent treatment of wastes from process equipment for production of technical fabrics with impregnation from synthetic fibers involves introduction of water-soluble reagents of coagulant – aluminum hydroxochloride and flocculant – polyacrylamide, mixing, maintenance (coagulation), separation of formed coagulum by settling and filtration with its subsequent utilization, at that, first, preliminary preparation of coagulant solution in form of 54 % aqueous solution of aluminum hydroxochloride and solution of flocculant in form of 0.1 % aqueous solution of polyacrylamide, after which they are mixed at ratio of 0.7:2.5 and then obtained solution is added to wastes at ratio of solution : wastes – 1:10 respectively, at waste temperature of 25–35 °C and pH 5.11–5.31, wherein during filtration, homogeneous mono-mineral fine-grained quartz sand is used as the filter material, and the filtered coagulum is subjected to squeezing and subsequent recycling.

EFFECT: simple processing and shorter processing time.

1 cl, 3 tbl

Description

The invention relates to a method for the reagent treatment of waste from washing technological equipment for the production of technical fabrics

impregnated from synthetic fibers contaminated with an impregnating solution containing harmful organic substances to be disposed of.

The choice of waste treatment method for an enterprise depends on many factors:

- amount of waste;

- the possibility and economic feasibility of extracting impurities from waste;

- requirements for the quality of purified water during its further use.

Waste from washing technological equipment for the production of technical fabrics from synthetic fibers with impregnation is contaminated with an impregnating solution and is an emulsion of hazard class 3. Waste contains water - 98.00%, phenols - 0.0004%, epoxy - 0.06%, latex - 1.8591%, diisocyanate - 0.08%, formaldehyde - 0.0005%, while phenols and formaldehyde and diisocyanate are harmful organic substances that must be disposed of.

A known method of water purification, which consists in introducing a coagulant and flocculant, mixing and separating the precipitate formed (see the description of the invention to the patent of the Russian Federation No. 2,530,042 “Method for the treatment of wastewater from leather industry”, IPC C02F 9/08, C02F 1/24, C02F 1/52, C02F 1/56, C02F 1/36, C02F 103/24, publ. 10.10.2014).

The known method is used mainly for wastewater treatment of leather industry.

In the known method, the wastewater is further averaged, the pH is adjusted and pressure flotation is carried out while the wastewater is saturated with air, sedimented, and then the sludge is removed.

The pH correction is carried out by averaging wastewater to a value of at least 10.5 by introducing a 4% suspension of slaked lime in the presence of ethanolamine borate at a flow rate of 4.0-6.0 mg / L. As an aluminum-containing coagulant, a 10% aqueous solution of aluminum hydroxochloride (GOHA coagulant) is used at a flow rate of 10.0-20.0 mg / l. Before pressure flotation, a 0.2% aqueous solution of flocculant and ethanolamine borate are added to the mixture at a flow rate of 15.0-25.0 and 3.0-5.0 mg / L, respectively. Saturation of wastewater with air during flotation is carried out by forced supply into their volume under pressure of 0.11-0.25 MPa of purified reverse flow after it is treated with an ultrasonic field with a frequency of 25-35 KHz with simultaneous supply of compressed air into it.

The known method is costly and complicated, which is its disadvantage.

A known method of purification of natural and wastewater, adopted as a prototype, which consists in introducing a coagulant and flocculant, mixing and separating the precipitate formed (see the description of the invention to the patent of the Russian Federation No. 2 174 104 "Method for purifying natural and wastewater from suspended particles", IPC C02F 1/52, C02F 1/56, C02F 103/02, publ. September 27, 2001).

The known method is used mainly in timber processing, rubber and metal processing enterprises, as well as in the treatment of domestic wastewater from solid dispersed substances (suspended particles).

The reagent used is the reaction product obtained by radical polymerization of acrylamide in aluminum hydroxide (GOHA coagulant) taken in the mass ratio (0.033-0.533): 1 in the presence of hydroxyalkyl-tert-butyl peroxide in the presence of Al (III) and polyacrylamide in the finished product ( 0.5-50): (0: 14-235) mg / L, respectively.

        The technical task and the result of the invention is the development of a reagent technology for processing waste from washing technological equipment for the production of technical fabrics from synthetic fibers with impregnation, which ensures the maximum possible removal of harmful chemicals included in the impregnation, at their maximum concentration in the form of condensed coagulum (sediment) while simplifying the process processing and reducing processing time.

The technical result is achieved by the fact that the method for the reagent treatment of washing technological equipment manufacturing equipment impregnated with synthetic fibers impregnated with water involves the introduction of water-soluble coagulant reagents — aluminum hydroxyl chloride and flocculant — polyacrylamide, mixing, aging (coagulation), separation of the resulting coagulum by settling and filtration, followed by disposal, while first coagulant solution is preliminarily prepared in the form of a 54% aqueous solution of hydroxychloride and aluminum and a flocculant solution in the form of a 0.1% aqueous solution of polyacrylamide, after which they are mixed in a ratio of 0.7: 2.5, and then the resulting solution is introduced into the waste at a ratio of solution: waste - 1:10, respectively, at the temperature of the waste 25 - 35 ^{° C} and pH of 5.11 - 5.31, thus when filtering as a filter material is homogeneous monomineral grained quartz sand, and filtered coagulum is subjected to pressing and subsequent disposal.

A distinctive feature of the proposed method is that when mixing a 54% aqueous solution of coagulant aluminum hydroxide chloride (GOHA) and a 0.1% solution of flocculant polyacrylamide (PAA A-150), the ratio of 0.7: 2.5, respectively, allows to achieve coagulation of waste , in the ratio of waste: coagulum - 1: 0.1.

The method of reagent treatment of waste from washing technological equipment for the production of technical fabrics impregnated with synthetic fibers is implemented as follows.

Wastes from washing technological equipment for the production of industrial fabrics with impregnation, including residues of the impregnating solution, are aggregatively stable colloidal systems in which organic substances are in an emulsified form dissolved in water and maintain a uniform distribution throughout the volume of the dispersed medium. Dissolved substances are present in the form of a stable emulsion, which are not retained by conventional filtering materials.

For effective reagent treatment of waste, first coagulant solution is prepared in the form of a 54% aqueous solution of aluminum hydrochloride and a flocculant solution in the form of a 0.1% aqueous solution of polyacrylamide (PAA A-150). Then the solutions are mixed, while mixing coagulant 54% GOHA and 0, A 1% PAA A-150 flocculant solution is most optimal for the coagulant: flocculant ratio - 0.7: 2.5, respectively. Then, the prepared solution of the coagulant and flocculant is poured into the waste in the ratio of solution: waste - 1:10.

The addition of both a coagulant and a flocculant at the same time leads, as a rule, to better results than when they are used separately, since in this case the coagulant binds pollutant ions, and the flocculant increases the particles and ensures greater coagulum compactness.

Using a pre-prepared solution of coagulant and flocculant allows you to achieve coagulation of waste, in the ratio of waste: coagulum - 1: 0.1. Examples are given in table 1.

Reagent waste treatment carried out at a temperature of 25 - 35 ^o C. At a temperature of over 35 ^{° C} the coagulation process will be slow or will not coagulate process. At temperatures below 25 ^{° C} the coagulation process will take place with the formation of small-sized flakes, which makes filtration.

The optimal pH during coagulation is in the range of 5.11-5.31.

The results of coagulation using a solution of GOX and PAA A-150 are shown in table 2.

After completion of the coagulation process, the resulting coagulum is filtered from water through a sand filter using a Buchner funnel on a Bunsen flask under a small vacuum to speed up the filtration process.

As filter material, homogeneous and monomineral fine-grained quartz sand with a diameter of 1.2 mm, passing only water (liquid phase), is used, but there is no coagulated waste.

The filtered coagulum is pressed to further separate the filtered water (liquid phase) in order to reduce the amount (volume) of coagulum supplied for disposal.

Dehydrated sludge is sent for disposal.

With the further use of filtered water, for example, for discharge into a water canal, it is additionally purified by passing through an adsorbent, for example, cellulose-containing raw materials, for example, crushed cane stalks or wood flour.

The results of a quantitative laboratory analysis of filtered water (filtrate) are shown in table 3.

Table 1

No.
p / p The volume of waste, ml The volume of the solution of coagulant and flocculant, ml Weight coagulated coagulum,% one fifty 5 19.7 2 70 7 20.8 3 90 nine 21.4 4 110 eleven 21.2 5 130 thirteen 24.6

table 2

No.
p / p The ratio of coagulant and flocculant in solution Coagulation Assessment one 0.1: 0.1 Coagulation is incomplete, suspended particles are not formed 2 0.4: 1.3 Coagulation is incomplete, suspended particles are not formed 3 0.7: 2.5 Coagulation complete, large suspended flakes formed in the waste 4 1: 3,7 Coagulation is not complete, large suspended particles are formed and the flocculant polymerizes 5 1.5: 4.1 Coagulation is not complete, flocculant polymerizes, forming a film around the waste

Table 3

No.
p / p Identified Ingredients The concentration of the substance in the filtrate, mg / l Maximum permissible concentration of m.r., g / m ³ one Cyanides 0.04 0.1 2 Phenols 0,053 0.001 3 Formaldehydes 0,07 0.05

Claims (1)

A method for the reagent treatment of washing wastes of technological equipment for the production of technical fabrics impregnated with synthetic fibers, including the introduction of water-soluble coagulant reagents - aluminum hydroxochloride and flocculant - polyacrylamide, mixing, aging - coagulation, separation of the resulting coagulum by settling and filtration, followed by its utilization, characterized in that first, a coagulant solution is preliminarily prepared in the form of a 54% aqueous solution of aluminum hydroxochloride and a flocculus solution yant in the form of a 0.1% aqueous solution of polyacrylamide, after which they are mixed in a ratio of 0.7: 2.5 and then the resulting solution is introduced into the waste at a ratio of solution: waste - 1:10, respectively, at a temperature of the waste 25 - 35 ^° C and pH 5.11-5.31, while filtering, homogeneous monomineral fine-grained quartz sand is used as the filtering material, and the filtered coagulum is pressed and recycled.