RU2145574C1 - Method of sorption purification of liquid media from impurities - Google Patents

Abstract

FIELD: physico-chemical sorption methods of purification of liquid media from mechanical and organic impurities using unverifiable industrial waste as sorbent. SUBSTANCE: claimed is use of active carbon carrier for purifying sorbent which is unutilized sifted waste fraction of 1.0-4.0 mm in multiton production of palladium catalysts. Sifted waste is formed from carbon carrier resulting from coal dust and binding materials by granulation and steam and gas activation. Characteristics of sifted waste are as follows: bulk density is 0.5-0.6 kg/cubic dm; attrition strength of granules is at least 70.0%. EFFECT: cheaper process for purification of liquid media from impurities and longer service life of sorbent, and degree of purification is maintained at high level. 3 tbl

Description

 The invention relates to physicochemical sorption methods for the purification of liquid media from mechanical and organic impurities using irrevocable industrial wastes as a sorbent, in particular screening waste of a fraction of 1.0-4.0 mm active carbon carrier of the production of palladium catalysts, which their structural and sorption characteristics, can be used in any sector of the national economy, when solving technical and economic problems, and also find wide application as a sorbent, in the face of gas phase from similar impurities.

 A known method of purifying natural water from organic compounds by contacting water with a sorbent containing alumina modified with cadmium sulfide / 1 /.

 The disadvantage of this method is the complexity of the preparation of the sorbent and its high cost due to the use of expensive reagents. Moreover, in the process of preparation of the sorbent, a large amount of its own wastewater to be treated is formed.

 A known method of fine purification of water from organic and inorganic impurities, with preliminary water purification through porous plates, filtering through asbestos, and then through a mixture of asbestos with a cation exchange resin / 2 /.

 The disadvantage of this method is the complexity, cost, duration and multi-stage cleaning method, as well as the regeneration method, using a solution of hydrochloric acid (conc. 7-20%) for processing plates and asbestos, which does not exclude injury to staff and corrosion of equipment. The most effective are methods for cleaning liquid media from organic and inorganic impurities on activated charcoal, which have universal sorption properties.

 However, their use on a large scale is constrained by an acute shortage, as well as the high cost of the adsorbent and the starting material, in particular wood / 3 /.

 The problem of deficit and cost can be solved by the use of irrevocable (non-recyclable) wastes of large-tonnage production in technological processes and water treatment systems.

 Known purification of water from organic impurities using waste wine production - grape seeds, as a starting material for the adsorbent / 4 /.

The disadvantages of the known invention are:
1. Inaccessibility and special long-term conditions for the processing of seeds when receiving the adsorbent, with the formation in large quantities of their own wastewater requiring treatment.

 2. The bones used have a form strictly defined by nature, but often either large or small fractions of the adsorbent are required.

 3. The low density of the adsorbent does not exclude the possibility of its entrainment from a system with a purified liquid medium.

 4. The use of waste is shown only on artificial mixtures, with a small number of impurities and only in laboratory conditions, with strictly fixed organic impurities. Real liquid media have significant variations in composition (the quality and quantity of contaminants is unstable over time).

 The purpose of the invention is to reduce the cost of the process of cleaning liquid media from impurities and increase the service life of the sorbent while maintaining the degree of purification at a high level, using irrevocable industrial waste as a sorbent.

 This goal is achieved by using as a sorbent previously unused screenings-waste fractions of 1.0-4.0 mm of active recovery coal carrier of large-tonnage production of palladium catalysts. Screenings and waste are generated from carrier coal, which in turn is obtained from coal dust and binders, granulation and steam-gas activation.

Used dropouts have the following characteristics:
- bulk density, kg / dm ³ - 0.5-0.6;
- the strength of the granules for abrasion,%, not less than 70.0;
- mass fraction of grains of the working fraction (1.0-4.0 mm),%, not less than - 97.0
and have mechanical strength, high sorption capacity with respect to the deleted substance without destroying its desorption at elevated temperatures, the possibility of repeated long-term use (up to 2 ^years or more).

In laboratory conditions, the possibility of cleaning industrial solutions of ammonia from mechanical and organic impurities using the screening waste was used as an adsorbent:
- from mechanical impurities - carbonate solution (mass fraction of K ₂ CO ₃ - 30%) / tab. 1/;
- from organic impurities - stripping condensate / table. 2 /.

The cleaning was carried out on a stationary unit at a feed rate of 1.2 dm ³ / h to an adsorption column loaded with screenings and wastes with a working fraction of 1.0-4.0 mm in a volume of 0.1 dm ³ .

 The cleaning efficiency was checked by sampling before and after cleaning and analyzing them for the content of mechanical and organic impurities according to departmental methods.

As laboratory experiments have shown, the maximum possible cleaning is in progress:
- carbonate solution from mechanical impurities (% purification 90.0 - 96.7), (table. 1);
- Stripping condensate from organic impurities (% purification 99.0-99.5), (table. 2).

The proposed method for cleaning liquid media from impurities was tested for two years under industrial conditions of ANKhK JSC in kolnotnotnoy production of ammonia at the water treatment stage, in two organic sorption filters working in parallel, where organic impurities are removed from water to a content of less than 2 mg / dm ³ after filters /5/. Removal of suspended organic substances by adsorption is necessary, since organic substances at the subsequent stage of water treatment, during the partial desalination of water, can penetrate into the pores of ion-exchange resins and be deposited in them, as a result of which the exchange ability of the resin is impaired.

For two years, screenings-waste fractions of 1.0 - 4.0 mm loaded into the organofilter N 1 in a volume of 12 m ^{3 were} tested.

 The comparison base was crushed active charcoal BAU-B brand, fractions of 1.0-5.0 mm, constantly used in the water treatment system, at the same time loaded into the N 2 organofilter in the same volume with replacement after a year of testing.

Industrial tests were carried out under a stable technological regime with a water load of up to 140 m ³ / h for each filter and a pressure drop of not more than 0.8 atm, which corresponds to the regulated standards / 5 /.

 During the test, samples of river water were taken on a monthly basis before and after each filter and analyzed for the content of organic impurities (permanganate method for determining oxidizability).

 The test results are shown in table.3.

From the tabular data it is seen that the proposed method provides the required quality of the prepared water. With the initial oxidation of river water max to 5.1 mg / dm ^{3, a} decrease in pollutants was obtained for both organofilters in the range of 1.4-1.7 mg / dm ³ .

In the course of a two-year test, the quality of river water after treatment using screening waste (organofilter N 1) is not inferior to the quality of river water after purification using BAU-B (organofilter N 2) in terms of the content of organic impurities in it, and in some cases it exceeds / tab. 3 /. Thus, the possibility of implementing the proposed method is verified:
1) in laboratory conditions by cleaning working solutions from impurities: carbonate solution from mechanical impurities (% purification 90.0-96.7) and stripping condensate from organic impurities (% purification 99.0-99.5);
2) in industrial conditions at the stage of water treatment. The resulting quality of river water after filters according to the content of organic impurities of 1.4-1.7 mg / dm ³ met the required standards of the technological regulation (purification to the content of organic impurities less than 2.0 mg / dm ³ ) / 5 /.

 Therefore, the proposed method provides high quality cleaning of liquid media from mechanical and organic impurities and is more economical and reliable. At the same time, the assortment of durable and cheap sorbents is expanding with an increase in their service life ≈ 2 times.

Sources of information
1. Copyright certificate N 590261, cl. C 02 B 1/14, 1978.

 2. Copyright certificate N 346231, cl. C 02 B 1/14, 1972.

 3. Deep treatment and reuse of wastewater. Overview. M., Gosstroyizdat USSR, 1974.

 4. Copyright certificate N 939031, cl. B 01 D 15/08 (prototype).

 5. Technological regulations for the production of ammonia, JSC ANHK, 1989.

Claims (2)

1. The method of sorption purification of liquid media from impurities by passing them through the waste of activated carbon fractions of 1 to 4 mm, characterized in that the screening waste of the recovery active carbon carrier is used for the production of palladium catalysts obtained from coal dust and binders, while the water to be purified pass at a speed of 140 m ³ / h 2. The method according to claim 1, characterized in that the used screening waste has the following characteristics: bulk density of 0.5 - 0.6 kg / dm ³ , the abrasion resistance of the granules is at least 70%, the mass fraction of the working fraction is 1 to 4 mm not less than 97%.

Images