DD153810A1 - TREATMENT OF LIQUIDS CONTAINING GELOESTE, EMULSIFIED OR COLLOIDING MATERIALS - Google Patents

Abstract

The invention relates to a process for the continuous chemical treatment of dissolved, emulsified and / or colloidal substances containing liquids, especially effluents and for flocculation and gravitational separation of these impurities and a device for carrying out this method. The liquid mixed with chemicals is introduced into the mixing chamber by means of an air flow, flows down there and is mixed with the newly entering liquid in the process. This recirculation of the flakes reduces the need for chemicals. The impurities floated upwards and floated with the air bubbles are scavenged from the surface of the liquid. The device according to the invention consists of three fluid volumes, a chemical mixing and precipitation chamber defined by a wall t deep b, a fluff forming and flotation space concentrically surrounding it, and a settling space.

Description

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Treatment of dissolved, emulsified or colloidal substances containing liquids

Field of application of the invention:

The invention relates to a process for the continuous chemical treatment of dissolved, emulsified and / or colloid-containing liquids, in particular waste water, for flocculation and gravitational separation of these impurities (flooding and settling) and a device for carrying out this process.

Characteristic of the known technical solutions:

In the known methods for wastewater treatment, the impurities are dissolved or emulsified, or colloid wastewater containing dissolved impurities are purified in several stages. In the individual purification stages are generally first the lighter impurities (fat, oil) floated, then the chemical waste to coagulate and flocculation are added to the wastewater to be purified, then the wastewater is passed through appropriate facilities for the purpose of settling. In the known methods become essential

larger amounts of chemicals are added than the amount calculated on the basis of the zeta potential. As a result, significantly more sludge is formed, increasing the cost of chemicals and debris removal (Mucsi-Urbanyi: Olajtartalmu szennyvizek tisztitäsänak ujabb hazai eredmenyei, 3rd VizminösSgi es Viztechnolögiai Konferencia, Budapest, 9-13 Oct. 1979). The amount of chemicals used for cleaning can be reduced, but by intensifying the cleaning processes «

In some recent processes, the resulting sludge is recycled (recirculated), thereby reducing chemical consumption. " The sludge is stirred by means of a mechanical stirrer (HU-PA T-Il 720). However, very expensive devices with long drive axes and expensive constructions, especially for reducing the rotational speed and speed control, etc., are required for such processes that the flocculation often causes the floccules to disintegrate, as a result of which their surface-active action becomes less pronounced · They are therefore more difficult to settle (R. Köhler: Wasser, Luft und Betrieb 19/1975 /, No. 2, pp. 72-77) o A disadvantage Also, that all impurities are separated by settling, although fats, oils and lighter floating impurities can be floated with a lower cost of chemicals, but a better efficiency (Speaker: Water Protection Water Abwasser, B. 19, meeting of 28.4 . - 30.4 · 1975 in Essen, S _e 505-509).

Object of the invention:

With the invention, the shortcomings of the prior art are to be eliminated.

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Explanation of the essence of the invention;

The invention relates to chemical treatment, precipitation, flocculation and recirculation of the floc, and settling of the sludge without mechanical stirring while the lighter components, if any, are chemically floated.

The method consists of three independently controllable Yerfahrensschritten: ·

a) The necessary chemicals and the liquid to be treated are mixed and contacted with each other, with bubbly air bubbles are mixed into the liquid.

b) As the flow rate decreases, the flakes are enlarged and coagulated, the active flakes are recirculated, and the lighter components are floated by means of the introduced air bubbles.

c) The coagulated with the chemicals substances are discontinued.

Embodiment:

The method is explained in more detail below with reference to the FIGURE.

The liquid enters through the line i in the area bounded by the wall 7 aeration and mixing section. Through line 2 10 air is introduced at the bottom of the vertical tubes. Due to the reduction of the specific gravity of the liquid, which occurs as a result of the introduction of the air, it rises upwards in the tubes. In the space between the tubes, the liquid moves downwards, causing intensive mixing in the space delimited by the wall 7. This will get out

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the line 3 escaping chemicals and dissolved in the liquid, emulsified or colloidal substances in intense contact with each other. In this space, the need for floating the lighter impurities tiny air bubbles are mixed further · The intensiveness of the through mixing strongly depends on the speed of the circulating liquid flow which can be regulated by the amount of the serving for mixing gas stream from _f.

Through the transport line 11 a regulated by means of the air introduced through the line 2a amount of mixed with the chemicals air is fed into the distribution chamber 12 and passes from there through the pipes 13 in the of the V / änden 7 »8 and 9 limited space, in which the liquid flows downwards at a detachable speed, while the lighter components, together with the air bubbles, reach the surface of the liquid. The floating on the surface impurities pass through the sump 14 and the conduit 4 from the device. In the space bounded by the walls 7, 8 and 9, the liquid flows downwardly at the rate dependent on the feed, whereby the process of flocculation and flocculation initiated by the addition of the chemicals continues to progress. The vessel containing the increasing flocs flows along the edge of the wall 9 in the direction of the arrows a and b. The contaminants adhering to the flakes settle in the space delimited by the walls 8, 9, 15 and 16, and the purified liquid flows over the overflow edge of the wall 16 into the plenum bounded by the wall 17 and exits through the conduit 5 the Apaarat. The settled sludge slides along the conical wall 15 and enters the shimmy room, from where it can be withdrawn through the pipe.

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The amount of liquid flowing downward in the space surrounding the walls 7, 8 and 9 can be regulated by the amount of air introduced into the transport pipe 11. The liquid flowing upwards in the tube 11 entrains the lighter floating particles. * As a result, the circulating flakes having an active surface come into contact several times with the impurities present on the liquid. "

The air used in the process not only serves for mixing, transporting and fuming, but also participates in the chemical process in many cases. If iron salts are used for the chemical treatment, flocculation requires oxygen which dissolves out of the air which has been passed through.

The air exits the upper, closed part of the flocculation and coagulation space via the mist eliminator 19 and the line 20 from the apparatus.

The process according to the invention has the following advantages:

- which for cleaning the dissolved, emulsified or colloidal · impurity-containing waste water necessary measures, d, h _# chemical treatment (precipitation, flocculating, coagulating), the floating and settling are done in a single operation,

the chemicals required are mixed in without mechanical stirring, by means of the air used for flotation,

the recirculation of the resulting flakes is also effected by air,

by means of the quantity of air passed through, mixing and recirculation can be regulated separately from each other,

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- Recirculation of the active flakes reduces the need for chemicals and results in fewer chemicals

  mud,

the flakes become larger during recirculation under favorable conditions and are well settable,

- When using iron salts as chemicals, the oxygen demand of the chemical reaction is covered by the introduced air.

The process can be used advantageously for the purification of fats, oils, detergents, organic substances, precipitable wastewater containing precipitated contaminants »

embodiments

The implementation of the method according to the invention is shown in Fig. 1 in longitudinal section * The drawing represents a characteristic embodiment, but also numerous other embodiments are conceivable without thereby exceeding the scope of the invention.

In the device surrounded by the cylindrical walls 15, 16 or by flat surfaces, the liquid flows through the space bounded above the wall 7, above and below, and through the space defined at the bottom by the walls 8, 9, and 18. In the upper part of the above closed by the wall 18 space is the sump 14 »In the space bounded by the wall 7 are vertically arranged, up and down open tubes 10» In the same room is the transport line 11, via the distribution chamber 12 and the Lines 13 with the space bounded by the walls 7 »8, 9 and 18 in connection ·

The device works as follows:

The liquid is passed through the pipe 1 under the pipes

- 7 ~

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guided, at the same time via the line 3, the necessary chemicals are added. Through line 2, air is passed under the tubes 10. As a result, the liquid is mixed in the vertical direction, the impurities are precipitated, flakes are formed, coagulated, and also the air bubbles necessary for flotation are mixed in.

In the transport 11 is also introduced from the line 2a, air, by their action in the distribution chamber 12 and the lines 13 of the liquid transport begins in the direction of Flockenbildungs- and Koagulier space. Meanwhile, the lighter contaminants, together with the air bubbles, reach the surface of the liquid and exit the device through the sump 14 and conduit 4. In the flocculation and coagulation space circumscribed by the walls 7, 8, S and 18, the liquid flows down at a rate proportional to the velocity of the liquid flowing in the transport conduit 11. In the conical space, the velocity of the liquid steadily decreases, creating favorable conditions for flocculation and growth. "

The amount of liquid flowing in the transport line 11 is greater than the amount of liquid fed for cleaning. Therefore, the liquid to be cleaned is moved several times in the space bounded by the walls 7, 8 and 9, where. with them the smaller, active flakes with it breaks, whereby a multiple break between the flocs and the impurities takes place. The amount of liquid moved by the transport pipe 11 depends on the amount of the supplied air, that is, h * h. the recirculation can be regulated by the amount of air flowing in the power 2a. The transport line 11 is shorter than the tubes 10, whereby the liquid containing the chemicals and the recirculated

-S

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lierte, flake-containing liquid can be effectively mixed together »

The chemically treated liquid flows under the lower edge of the wall 9 in the direction of the arrow a and loses part of its sludge content. In the further upward flow in the settling chamber and the small flakes are eliminated «The purified liquid passes over the upper edge of the wall 9 and exits through the conduit 5 from the device. The settled sludge slips along the conical wall 15 into the Schlannnraum and can be withdrawn through the line 6 »

The following example explains the treatment of waste water from a laundry. The wastewater contains 20 to 40 mg / 1 anionic detergent, 100 to 200 mg / 1 fat and oil and 200 to 500 mg / 1 suspended matter. It is with a volume speed of 4 n / h - after

previous adjustment and adjustment of the pH value - fed into the device according to the invention "0.5 g / l aluminum sulfate and 2 mg / l polyelectrolyte are added to the waste water. The amount of active flake-containing liquid circulating in the device is 16 to 20 m / h, i. 4 to 5 times the amount of waste water fed in. The purified water leaving the sedimentation zone contains 3 to 6 mg / 1 anionic detergent, 20 to 25 mg / 1 fat and oil and 20 to 50 mg / 1 suspended matter. The efficiency of the cleaning is (average values of the operation over several months):

Anion-active Y / Aschmittel 83 % fat u. Oil content 87.5 %

Suspended matter 90.5 %.

The resulting sludge accounts for 3 % of the wastewater volume fed in «

Claims (4)

-9- 223 4 6 I Invention claim: 1, Process for the continuous chemical treatment of liquids containing dissolved, emulsified and / or colloidal substances, for mixing the liquid with the respectively required chemicals by means of a gaseous medium introduced at the bottom of a vertical, symmetrical mixing section, ζ · Β. Air, for flocculating and separating the substances suspended in the liquid, in a device which, from its vertical axis of symmetry following radially in succession and concentrically arranged, contains a flocculation and coagulation mixing space and a settling space connected thereto, characterized in that the mixed with chemicals liquid with the help of a introduced at the bottom of the device via pipes in the mixing chamber gas stream in the flocculation and coagulation space, there flows down, the ever-increasing flake-containing liquid stream with the entering into the process, with Chemicals mixed, raw liquid stream mixed, whereupon the upwardly swept substances from the upper part of the flocculation and Koagulier space, the settled sludge from the bottom of the settling space and the purified liquid from the upper T _e il the settling space deducted · 2. The method according to item 1, characterized in that regulating the speed of the circulating in the mixing chamber liquid flow over the amount of serving for mixing gas flow. Method according to item 1 or 2, characterized in that the ratio between the raw liquid stream entering the process and the liquid stream passing through the fluffing and coagulating room is transferred over 223 465 regulates the amount of air flow used to move the latter, Method according to any one of items 1 to 3, characterized in that the velocity of the liquid flowing downwards in the flocculation and coagulating space is reduced continuously or in sections. Device for carrying out the method according to one of the items 1 to 4, characterized in that it consists of three liquid spaces of different purpose bounded by cylindrical walls or flat surfaces guiding the flow, namely a chemical mixture separated from a wall (7). and precipitation space (A), a flaking and coagulating flotation space (B) bounded by walls (7, 8, 9 and 18) and a settling space (C) bounded by walls (8, 9 »15 and 16). 6. The device according to item 5, characterized in that in the chemical mixing and Ausfällraum down and above open, vertical tubes (10) are arranged at the bottom, gas-distributing organs are. Device according to item 5 or 6, characterized in that a transport line (11) arranged in a chemical mixing and precipitation space (A) is connected via a distributor chamber (12) and lines (13) to the flocculation and coagulation chamber (B) is δ. Device according to one of the items 5 to 7, characterized in that in the upper part of the flocculation and coagulation chamber (B) a collecting trough (14) suitable for discharging the substances swept upwards is arranged. - 11 - 223 461 9. Device according to one of the items 5 to 8, characterized in that at the bottom of the settling space (C) of a conical wall (15) limited sludge space is provided · y \ page drawing. - 12 -