SU42515A1 - Chamber for biological wastewater treatment - Google Patents

Description

In biological treatment of sewage sludge is separated from water by sedimentation and then enters special rotting chambers in which it is completely decomposed under the influence of bacteria. The process of rotting sludge usually lasts about 3 months. The subject matter of the present invention is a significant acceleration of rotting sludge. According to the invention, three different methods are proposed for this purpose, which can be applied either individually or jointly.

In FIG. 1 and 2 show sections of two exemplary devices suitable for applying this method; FIG. 3 and 4 are exemplary implementation in two mutually perpendicular sections of the cleaning station with a sludge heater.

One of these methods is that rotting silt accumulating in the lower part of the chamber gradually or at intervals rises up almost to the surface of the liquid in the chamber so that the sludge, due to its weight, falls through the liquid back to the bottom. The effect of this technique is based on

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The following observations. Bacteria that cause decay are not found in the lower part of the chamber suitable for the existence of the environment, because in the deeper parts of the chamber there is an increase in the ability of water to dissolve carbonic acid harmful to bacteria, as well as increased saturation with methane gas, which is released by bacteria, and partially remains as bubbles around the bacteria. In order to remove these bacterial decay products from the lower part of the chamber, they used vertical axis baffles or tried to place sludge at the bottom of the chamber by letting in gaseous or volatile substances. However, these measures are not sufficient to achieve the desired results. According to the invention, all the settled down to the bottom of the rot chamber or constantly or at intervals rises to the level of the liquid so that the bacteria constantly return to the favorable medium in the upper part of the chamber, after which the sludge gradually falls through the liquid to the bottom of the chamber.

With this method it is possible to achieve a further advantage:

when the device for lifting sludge in the opposite direction is started, spongy sludge floating on the surface of the liquid, which was badly rotten and hardly removed in the chambers of previous constructions, is sucked from the surface of the liquid down to the heavy settled sludge, is retained and decomposed last. The sponge-sludge particles returning to the surface are impregnated with well-decomposing (active) sludge particles and due to this they themselves quickly decompose so that it is possible to remove them together with the others.

FIG. 1 shows a separate rotting chamber with a sloping bottom to which one or several suction pipes are connected to the pump 2 located outside the chamber. These pipes suck sludge from the bottom and feed it under pressure using one or many pipes near the liquid level, approximately at the normal level, it is 8 back into the rotting chamber.

FIG. 2 shows a two-story. a cleaning station, the upper part of which is occupied by a settling chamber 4, through which a constant, slowly flowing stream of waste water to be cleaned passes, and the sludge in the wastewater is lowered to the bottom of chamber 4 and through holes in the bottom 5 passes into the lower rotting chamber 6 .

Such two-story treatment plants are essentially already known. In the rotting chamber B, according to the invention, suction pipes 7 are located, which almost reach the bottom of the chamber 6. A centrifugal pump 10 is placed in the pipes 7 and is driven by a motor 12 outside the chamber. This pump raises the sludge from the bottom of the rot chamber 6 to the surface of the liquid 8, which then slowly descends through the liquid back to the bottom.

In order to trap gases of rot, but to dispose of them, the rot chamber in both cases is closed from above. When pumping up the sludge, the gases located on individual bacteria and the smallest particles of sludge expand and separate from them, and this process is enhanced by the mechanical action of the pump. The amount of carbonic acid dissolved in elevated silt water is further reduced by mixing with wastewater above sludge deposited on the bottom.

When starting up the sludge lifting device in the reverse direction, sponge sludge floating on the surface of the liquid in the rot chamber is sucked in and fed under the surface of the precipitated sludge, and at the same time the spongy sludge is partially crushed.

The effect of this cleaning method can be enhanced by a second intake, consisting in the frequent stirring of the old activated sludge in the chambers of the fresh sludge. This technique is based on the following observation: the older the sludge becomes, i.e., the further the process of decomposition of organic parts advanced under the influence of bacteria, the less favorable is the environment for the existence of bacteria, so that they are modern in the decomposition of sludge in most of completely die out. If you mix old sludge with fresh or young, slightly decomposed sludge, then, on the one hand, bacteria enter the sludge from fresh or young sludge, on the other hand, new nutrients that still exist in old sludge receive new nutrients. Enhancement.

Until now, old sludge has also been added, but only in order to prevent acid fermentation in fresh sludge. For these reasons, at least 1/3 of its amount of old sludge is added to the fresh sludge, or the necessary amount of old sludge is collected from the rotting chamber and the appropriate amount of fresh sludge is introduced there, or the proper mixture of fresh and old sludge is directly introduced. This technique has so far been applied only once, and then either the entire contents of the rot chamber were left alone until the sludge decomposed completely, or a little fresh sludge was added daily to a flat oblong rot rotting chamber at one end, and at the other end it was removed. amount of old sludge.

According to the invention, repeated, frequent mixing of all the old sludge in the rotting chambers with fresh sludge is performed until the sludge is completely dispersed, and small amounts of the fresh mixed with a are mixed in so well with the old and decompose so quickly that they can be removed with disintegrated sludge without harm for its further processing.

The effect of this technique at the beginning of the proposed method of accelerating the decomposition of sludge can be enhanced even when the third means is dumped, namely heating the sludge to be decomposed. Until now, a rotting chamber was heated with a number of coils inside the chamber or by supplying warm water to the rotting chamber, or release at the same time, its amount of water from the chamber.

According to the invention, it is preheated which is introduced into the chamber, fresh sludge or already otherwise susceptible to prior rotting. In this case, it is sufficient to warm the fresh sludge to a temperature a few degrees higher than the optimum temperature of the rot chamber — normally by 25 °. Since fresh sludge, in contrast to the old, does not corrode metal and, moreover, the vessels for heating fresh sludge, as opposed to rotting chambers, can be emptied daily, this heating of fresh sludge does not result in the sludge being heated help coils.

Heating of fresh sludge is combined very successfully by adding fresh sludge to all sludge and feeding active sludge to the surface of the liquid, as in this case it is possible to add fresh or young sludge to them but to the described method. In order to maintain a constant temperature in the rot chamber at the desired level, it is necessary to isolate the rot pool well, then to cover a slight heat loss, it is enough to heat the sludge introduced into the chamber to a temperature that lies only slightly above the optimum rot chamber temperature. Otherwise, if the injected sludge is heated to a temperature much higher than 25 °, for example, to 45 ° or even higher, the bacteria in the sludge would be killed.

According to the invention, good heat insulation of KaiViepbi rot can be achieved not only with the help of the outer and inner insulating layer, but also surrounding the rotting chamber, if possible from the ground surface to the bottom of the chamber, with a settling basin, which in this case cannot be located directly zi camera rot. Since the soil in which the rotting chamber is located is usually much colder than the wastewater to be treated, having a normal temperature of 10-12 °, the contents of the settling basin are better insulation for the rotting chamber than the soil.

FIG. Figures 3 and 4 are shown in two mutually perpendicular sections; an exemplary cleaning station is not executed with the use of additional measures.

In the rotting chamber b are, as in the exemplary embodiment of FIG. 2, suction pipes 7 with a centrifugal pump 10. Through these pipes, precipitated sludge, which is in chamber b, rises constantly or at intervals to liquid level 8. The rot chamber b is surrounded by one or many settling basins 14, which income on the ridge to the ground level and to the bottom of the rot chamber. In the settling basins 14 there are at the bottom of the chamber / 5 for the deposited., From which pipes 16 are led to the chamber / 7, located above the rotting chamber b. Through pipes / b, fresh sludge is fed into chamber 17 by means of a pump. Chamber 17 is equipped with coils 18, heated from any heat source and heating sludge in chamber 17, up to the temperature of the rotting chamber b, into which the heated sludge enters from above continuously or at intervals through tubes 19 supplied with the gates. sludge with the old supplied suction pipe 7. The rotting chamber b can also be provided with an insulating layer 20 and, moreover, with voids 27 for blowing insulation.

If fresh sludge contains a large amount of water (98-99%), it is recommended that, in order not to warm this amount of water, to divert some of the water before artificial preheating. On the other hand, in cases where fresh sludge contains a relatively small amount of water, or when for other reasons the amount of fresh sludge added daily to the old one is not enough to introduce heat in the amount required for a rotting chamber without too much heating. fresh sludge, you can artificially dilute the heated fresh sludge by adding the right amount of water. The added water can be taken out of the rot chamber. It is also possible, moreover, to separately heat the water from the rot chamber and pour it back into the rot chamber.

These measures make it possible to extract enough gases from the chambers of rotting to cover their own needs. Moreover, thanks to these measures, the time required for complete sludge killing is reduced to 2/3 Ido and 1/2 the time needed so far, which leads to a corresponding decrease in the volume of rotting chambers.

Subject pa tent and.

1. A camera for sludge extinguishing of sewage liquids, characterized by using a pumping device 2 to continuously or periodically raise sludge sludge from the bottom of the rotting chamber without contact with air to the level of liquid 8 in order to accelerate the decomposition of sludge when it is circulated through the rotting liquid of the chamber (Fig. 1 and 2).

2. The form of execution of the chamber for the sludge rotting out of the waste liquids, referred to in paragraph 1, characterized by applying heating in a separate chamber / 7 by the swenslog sludge coil 18 to or slightly above the temperature of the liquid in the rotting chamber and periodically mixing it to the old silt} in chamber 6 either with its preliminary compaction at rotting, or with its preliminary enrichment with water from the rotting chamber with a lack of water in it (Fig. 3 and 4).

3. In the sludge rotting chamber designated in paragraph 1, use heat insulation for the decay chamber b by placing it inside the settling basin 14 with water (Fig. 3).

E to patent of M.T. Pruss and G. Blunk

No. 42515

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