SU808379A1 - Method of biochemical purification of waste water - Google Patents

Description

The invention relates to the treatment of wastewater from industrial plants and can be used in the chemical paper, wood chemical industry, as well as in enterprises of other branches having a biochemical wastewater treatment. In the industry, the biochemical purification method is widely used. The biochemical method does not allow the purification of wastewater from biochemically non-oxidizable substances; moreover, this method is not waste-free. Excess activated sludge is accumulated as a waste in biochemical purification, and then converted into fermented sludge. A known method of cleaning industrial wastewater by the biochemical method with their subsequent purification by the sorption method. In this case, activated anthracite, which is more effective than industrial active carbons and has a slightly lower cost, is used as a sorbent. To obtain the sorbent, anthracite is crushed to a granule size of 0.25-1 mm and activated with steam and flue gases at 830-90 ° C. After: use, the sorbent is regenerated by heat treatment at 6007 ° C: l2L However, the sorbent cannot be regenerated infinitely, it loses its activity (cannot be recovered by regeneration) and turns into waste. Thus, this purification method is not without drawbacks: it is not waste-free (waste is excess active sludge and fermented sediment from the biochemical purification stage and a sorbent from the sorption purification stage restored by regeneration); and also requires the cost of regeneration of the sorbent. The purpose of the invention is to create waste-free production with a similar degree of purification.

The post goal is achieved by adding 10–15 wt.% Activated sludge to the suspension – water – adsorbent, 10–15 wt% sludge, 10–15 min., Air is suspended in the air, 10–15 min., The sediment is used and the bluid pellets are not used. .

The method is carried out as follows.

The waste water is treated in a controlled manner, first by biochemical and then by sorption methods. As a sorbent, carbon residue formed during the burning of bark and other wood waste in steam furnace fire chambers (CDT) and trapped gas of smoke gases using ash collectors is used. The sorbent has a constant fractional composition, bulk density, sorption activity for iodine, which makes it possible to characterize it as a product with certain physicochemical properties.

KDT sorbent is bilayer and its regeneration is inexpedient. The spent sorbent is utilized by obtaining heat briquettes from it, and fermented sludge or activated sludge from biochemical purification is used as a binding agent for briquettes.

The fermented sediment or activated sludge is added to the water-adsorbent suspension in an amount of 10-15 wt.% Dry adsorbent. This makes it possible to produce durable briquettes (crushing strength 4, -1.1 10 Pa), corresponding to the specifications for charcoal briquettes used as fuel in railway transport.

The introduction of the water-adsorbent to the suspension with a shrinkable precipitate or active ip promotes the coagulation and precipitation of small particles of the adsorbent from it. However, to achieve rapid deposition of particles of adssbent, the mixture is purged with air for 10-15 minutes. The sedimentation rate -1 in this case is increased 10 times.

Example. The biochemically purified wastewater {COD-400 mg / l) is fed to the adsorbing, to which carbon dioxide KDT (0.14 mm fraction) is added in the amount of 6.0 kg / m water. A suspension of the sorbent in water is stirred for 20 minutes with air or with a mechanical stirrer and filtered through a filter from the same filter (fraction 0.5-3.0 mm). The content of organic impurities in the filtrate is determined and the degree is calculated. aftertreatment, which is 59%.

The powder sorbent remaining on the carbon filter is removed by reverse blowing with air and sent to a mixer, where fermented sediment is added as a coagulant and a binder in an amount of 15% by weight of carbon.

sorbent in terms of dry substance. The moisture content of the fermented sludge is 96%. A suspension of powdered sorbent and fermented sediment in the water is mixed in the mixer with air in flow -

10 min and sent to a sump where it is settled and the sedimented sediment with a humidity of 60-62% is briquetted over a pressure of 2.510 Pa. The resulting briquettes are dried at a temperature and

tested for strength. The strength of the crush crushing briquettes obtained under these conditions is 1.11 O Pa, which corresponds to the technical conditions for charcoal

briquettes intended as fuel in rail transport. Purified and clarified water is fed into the collector of clean water and further to discharge.

The effectiveness of the purification of biochemically purified waste water powdered sorbent is given in Table. one.

In tab. Figure 2 shows the conditions for obtaining briquettes from spent spbent and fermented sediment or activated sludge and their strength.

The effect of the time of air flushing of the mixture of adsorbent-fermented sludge on the extent of its settling is presented in Table. 3

. The proposed method of wastewater treatment provides for the use of spent KDT sorbent and fermented sludge or activated sludge for the production of fuel briquettes.

At present, this sorbent, fermented sludge and activated sludge are production waste and pollute the environment. The KDT sorbent in the form of coal particles is carried away with the flue gases of the boiler rooms into the atmosphere and carried by the wind for long distances; Abnormal sludge and activated sludge is dumped onto the sludge floors of enterprises, and the sanitary condition of the adjacent area and occupies large areas.

Nl tables

Experiments using active ipg

Table 3

rem purge

Speed . suspension of suspension, m / s by air,

6.7,

About 5.3flO

ten

-s

4.4.10

15

G 5

2,710

45

-5 2,

6O

table 2

Formula inventions

The method of biochemical sewage treatment with subsequent purification with a carbon sorbent is distinguished by the fact that, in order to create waste-free production at a similar degree of purification, 10–15 wt.% Of the dry sorbent is added to the adsorbent water suspension. blow air for 10-15 minutes, defend, separate the precipitate, which is used to produce fuel briquettes.

7S063798

Sources of information, 2. Kievsky M.I., Evstratov V.N.

taken into account in the examination "Semenyuk V.D. Wastewater treatment

1. Poruikiy G.V. Biochemical enterprise of chlorine industry

cleaning of waste water organic products, M., Himi, 1978, p., 168 production. M., Himi 1975, p. 256., 170.

Claims (1)

Claim A method for biochemical treatment of wastewater followed by purification with a carbon sorbent, characterized in that, in order to create a waste-free production with a similar degree of purification, a fermented sludge or activated sludge is introduced into the water-adsorbent suspension in an amount of 10-15 wt.% Dry sorbent and purged with air for 10-15 minutes, defend, the precipitate is separated, which is used to obtain fuel briquettes.