DE2106926A1 - Process for chemical waste water purification and device for carrying out the process - Google Patents

Description

Patent attorneys
bipl. Ing.Hans WestphftV
Dipl. Ing. Klaus Westphal
Dr.rer.nat. Otto Buchner

773 Viilingen / Black Forest
Karlsruher Strasse 18

Bbrrn A.ffl.C. Aktiengesellschaft , CH-6374 Buochs (Switzerland)

Process for chemical waste water purification and device for carrying out the process

The present patent relates in particular to a method for chemical waste water purification by the post-precipitation method for chemical precipitation of phosphates or to achieve other plocking processes, and a device for Implementation of the procedure.

In already known devices of this type, the wastewater to be treated is directly in the depth of the basin initiated above the bottom of the pelvis in the center. Above the "introduced" is a fast-running agitator

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Werk, which the_ added in the same place necessary precipitants mixed intimately with the wastewater to be cleaned

After mixing the wastewater to be cleaned with the precipitant, the resulting mixture is in one tubular inner part of the basin upwards, then over an overflow edge into another, the tubular one Fc Vussenkranz surrounding the inner part, which is also round, and then back down to the Beekenboden directed.

after the addition of the precipitant takes place in the above tubular inner part, the formation of the flake sludge instead. This flaky sludge has to go into this pipe first upwards "to be transported in its natural settling behavior only after the flow reversal to be supported · Part of the flaky sludge that has accumulated on the pool floor is passed through several openings fed to the lower inlet end of the tubular inner part in order to make better use of the remaining flakes to achieve contained precipitants

However, these known devices have the disadvantages that the wastewater inlet, the mixing process, the mixing unit located at the bottom of the basin

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as well as the Floekenschlammruelcfuhrung relatively difficult are to be controlled

The purpose of the invention is to create a method and a device which does not have these disadvantages, i.e. in which the flocculent sludge is also in the Basin is deposited, all essential processes can be easily monitored at all times, and in addition the natural settling process of the flocculent sludge is supported.

The method according to the invention is characterized in that that the wastewater to be treated and the precipitant are placed in a tank located in the upper part of a basin Feeds mixing zone and intimately mixes with one another there, then the mixture down through a flocculation zone into a Sedimentation zone, where the flake sludge settles, and then the water freed from the flake sludge upwards into one separated from the mixing zone and the flocculation zone by a wall arranged in the basin Clear water zone conducts

It is expedient to have the wastewater to be treated and the precipitant for intimate mixing directly below the process water level the mixing rotor located

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For better utilization of the Pällungsniittels it is advantageous if through at least one riser reaching into the sedimentation zone, part of the sedimented flake sludge back into the mixing zone initiates, and expediently by using the suction effect of the with the riser cooperating mixing impeller supplied part of the sedimented flake sludge to the latter

The invention also relates to a device for carrying out the method according to the invention, which is characterized in that it has a basin, which by an upward over the setting in operation Water level out and down into the sedimentation zone into a die Mixing zone and the flocculation zone containing the first space and a space adjacent to this space, the clear water zone containing second space is divided, and that a feed line for supplying the wastewater to be treated and the Precipitant in the mixing zone located in the upper area of the first room and a mixing unit for mixing of the wastewater to be treated and the precipitant are provided in the mixing zone ·.

It is advantageous if the basin is through the baffle into a centrally located, the mixing zone and the flocculation

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zone containing the first room and a second room surrounding this room and containing the clear water zone, is divided.

The mixing unit is expediently provided with a water level directly below the operating water level is provided with the mixing rotor.

In the following the invention will be illustrated by way of example with reference to the drawing;

FIG. 1 shows a section through a first exemplary embodiment of one according to the invention Facility;

FIG. 2 is a plan view of the device shown in FIG. 1;

FIG. 3 shows a section through a second exemplary embodiment of a device according to the invention; and

FIG. 4 is a plan view of that shown in FIG Facility·

The device shown in Figures 1 and 2 has a frustoconical basin 1, which by a at the top beyond the water level 2 that is established during operation and down to the sedimentation zone 3 extending baffle 4 located in a Z3ntrisch, the Mixing zone 5 and the flocculation zone 6 containing the first space

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^"6 ~ 2106928

_{and a second room 9 f} surrounding this room 7 and containing the clear water zone is divided.

To supply the wastewater to be treated and the precipitant in the upper area of the first Room 7 "located mixing zone 5 is a supply line provided, which is located directly below the operating water level 2 directly to the suction side Mischicreisel 11 of a mixing unit 12 leads. Of the Mixing gyro 11 is arranged so far below the water level 2 that it does not have any during the whisking process Saiierstoff 'in the 7 / water brings

- ¹ U '

Since the precipitant already before entering the Mixing gyro 11 is introduced into the waste water supply line 10 via line 13, a first takes place from this entry point to the suction side of the mixing gyro 11 rough mixing of the wastewater to be cleaned with the

Precipitants

The mixture consisting of the wastewater to be cleaned and the precipitant flows after intensive mixing through the mixing impeller 11 from the Ilischsone 5 down into the subsequent flocculation zone 6, in which the flocculation and flocculation takes place with the help of the agitating flow generated by the mixing impeller 11.

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~ ⁷ ~. 210692a

The flocculation zone is used to improve the cooling flow 6 strand with internals 14, which are designed in such a way that they cause a screw line-shaped movement of the from see below effect of cleaning wastewater and precipitants when passing through the flocculation zone 6 ..

Since the flaky sludge that forms is specifically heavier than Is water, it settles in the sedimentation zone 3. The water from which the flake lamb has been removed then flows in at the top in a baffle 4 separated from the mixing zone 5 and the flocculation zone 6 by the immersion wall 4 attached to the basin 1 Clear water zone 8 »At the upper end of the clear water zone 8 is a discharge weir 15 for discharging the chemically cleaned Sewage provided.

Around. the active precipitants still present in the flake sludge to be able to use in the continuous flocculation process, is one from the sedimentation zone 3 to the suction side dos Liischkrcisels 11 reaching riser 16 to the adjustable Recirculation of flocculent sludge deposited in the sedimentation zone 3 into the mixing rotor 13 is provided. Through the Effect Cer suction force of the mixing impeller 11 constantly flows into an adjustable Kenge of the separated flake loop the Ifiischsone 5 back. This amount can be a multiple of Throughput of the facility. Through this constant circulation it is achieved that the flakes in the flake any active precipitants still contained are also used

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and thereby result in a Pällungcmitteleinaparung. Since also part of the already cleaned water on this one Participates cycle, the Iiohwasser in the mixing zone 5 is continuously diluted with this, which an equalization of Has a load impact.

The flakes, sludge, which constantly accumulates through the flocculation process, becomes according to the increasing rate of growth via the Flooicenschlammabzug 17 from the sedimentation zone 3 removed The flocked sludge extractor 17 can e.g. with the help of a photocell control with two photocells be fully automated. If the mud level rises to the Height of the upper photocell, then the sludge drain valve is opened through the interruption in the passage of light. This remains in the open position until the lower photocell is caused by the drop in the sludge level Light has passed and the sludge drain valve closes. Due to that which occurs in the separation zone of water and sludge a fully automatic sludge removal is possible for clear separation.

A major advantage of the device shown is that all operations necessary for the flocculation process such as mixing, flocculating, sedimenting and recirculating in carried out a structural unit and housed in a relatively small space v / ground. As the wastewater to be treated directly below the operating water level 2 in the

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Mixing zone 5 is initiated is a constant control option guaranteed »

Due to the arrangement of the mixing unit 12 at the level of the operating water level 2, the mixing unit 12 is at all times accessible for control purposes without emptying basin 1. Long drive shafts are also avoided. Since that The mixing unit has practically no delivery head to cope with, a large mixing and circulating effect is achieved. .

The inventive design of the device is the flaky sludge that forms after the addition of the precipitant in its natural sedimentation behavior already supported in the flocculation zone 6 .. At the same time, due to the rotational movement that occurs there, the The flocculation process is favored.

In FIGS. 3 and 4, a second exemplary embodiment of a device according to the invention is shown, which essentially only differs from that shown in FIGS. 1 and 2 by a different shape of the basin 1 Embodiment differs. Thus, a description this facility is omitted, since the same applies as described above. All identical parts are provided with the same reference symbols v / ie in FIGS. 1 and 2.

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Claims (1)

-ίο- 2106928 i: a ro VfTiI 'i τι ·: «τ ·» -, rns' "» Tl ~ ir> 1. Process for chemical wastewater treatment The subsequent precipitation process, in particular aur chemical Precipitation of phosphates or the achievement of other Plockungs \ orgän £ en, characterized in that the wastewater to be treated and the filler into one in the upper area of a Becicena oak "supplies located tliöchaone and there inrii ^; with each other mixes, then passes the mixture down through a flocculation zone into a sedimentation sonc, where the Flockenachlcauia aba et st, and then that of the Flockensciilarnm freed water upwards into one of the Kischsone and the Plockungczone by an im Basin arranged 7 / andung separated Elarv / as scr zone directs. 2. The method according to claim 1, characterized ^ ekennseichnet ,. that you the su treated wastewater and the precipitant for intimate mixing one immediately below the operating water level located Kischkreisel feeds. 3. The method according to claim 1 or 2, characterized in that 209832/098 « that one by at least cine down to the Sedincntaticncsone Reaching riser part of the sedimentation area Floclionschlanmes reintroduces into the mixed zone. A. Process according to Claims 1, 2 and 3, characterized in that a portion of the sedimented flocculant lock is fed to the latter by utilizing the suction effect. 5. The method according to claim 1, characterized by, dcins the precipitant to the "au" treated Waste water is added and together via a supply line the Iischzone is filled. 6 '. Method according to claim 1, characterized in that. that means arranged in the Floc3Liingszone internals along a helical 'Hess passes, which consists of waste water to be cleaned and from Füllimgsrait.tel mixture therethrough. 7 · Facility for carrying out the procedure according to Ansprtieh 1, characterized by that it is a Basin (l) cries, which by an upward over the Y / water level (2) that is set in operation and me down to the sedimentation zone (3) extending baffle (4) into a mixing zone (5) 209832/0989 • and the first space containing the Fl ο clamps ζ one (6) (7) and a second room (9) adjacent to this room (7) and containing the Klarwasserzoiie- (8) is divided, and that a feed line (10) for supplying the wastewater to be treated and the Precipitant in the mixing zone (5) located in the upper area of the first space (7) and a Mixing unit (12) for mixing the to be treated W wastewater and the precipitant in the I.Tic chzone (5) are provided. 8. Device according to claim 7, characterized in that that the basin (1) through the baffle (4) in a centrally located, the mixing zone (5) and the First space (7) containing flocculation zone (6), and a space (7) surrounding this, the Klai water zone (8) containing second space (9) is divided. 9. Device according to claim 8, characterized in that that the basin (1) has a conical or frustoconical shape, with an increasing cross-section directed upwards and vertically extending longitudinal axis. 10. Device according to claim 8, characterized in that the basin (1) has a pyramidal or pyramid-shaped trumpet Has shape, with increasing 209832/0989 Cross-section directed upwards and vertical longitudinal axis. 11. Device according to claim 7, characterized in that that the mixing unit (12) with one located directly below the operating water level Mixing impeller (11) is provided. 12. Device according to claim 7 or 11, characterized in that at least one of the mixing zone (5) reaching into the sedimentation zone (3) Riser pipe (16) for the return of flocculent sludge deposited in the sedimentation zone (3) is provided in the mixing zone (5). 13. Device according to claims 11 and 12, characterized in that the riser (16) with the Is connected to the suction side of the mixing impeller (11). 14 · - Device according to claim 7 »characterized in that the supply line (1O) for the Wastewater in front of its junction with the suction side of the mixing impeller (11) with the addition of precipitant (13) is connected. 15. Device according to claim 7, characterized in that the flocculation zone (6) is provided with internals (14) is, which are designed such that they are a 209832/0980 .-14 - helical movement of the from to be cleaned Mixture of waste water and precipitants when passing through the flocculation zone (6). 16 .. Device according to claim 7, characterized in that one in the sedimentation zone (3) reaching Flocked sludge discharge (17) is provided. 209832/0989 Blank page