JP4246087B2 - Oil-containing wastewater treatment equipment - Google Patents

Description

  The present invention relates to an oil-containing wastewater treatment apparatus (system), and in particular, treats an oil-in-water (O / W) type emulsion wastewater containing a high concentration of oil and having a pH of about 7 or more using a coagulation reaction. It relates to a preferred invention.

As an apparatus (system) for treating oil-containing wastewater, there is, for example, Patent Document 1 (first column 21 line to second column 13 line and FIG. 2). In this system, the oil-containing wastewater is subjected to an emulsion break with an inorganic flocculant in a rapid stirring tank (2), and then the flocs are coarsened with an organic flocculant in a slow stirring tank (24). Air bubbles are caused to adhere to the levitation separation tank (25) for solid-liquid separation (scum separation), and the scum water is dropped by the concentrator (29) and incinerated. (Note that the reference numerals in parentheses are those in FIG. 2 of the patent document.)
Moreover, although the apparatus is not specified, there exists patent document 2 etc. as what described the processing method of the oil-containing wastewater using a coagulation reaction.

Furthermore, in Non-Patent Document 1, the inorganic flocculant acts to generate micro flocs by emulsion break, that is, coagulation, and large flocs are generated by organic flocculant (polymer flocculant) and settled. It is stated that the speed is increased significantly.
Japanese Patent Publication No. 4-10397 JP-A-60-202787 “Chemical Engineering Association” “Chemical Engineering Handbook 4th revised edition” (Sho 53-10-25 Maruzen, p1092) And the present inventors are coagulating using the above-mentioned inorganic coagulant and organic coagulant (polymer coagulant) In the method of wastewater treatment using reaction, O / W type emulsion wastewater containing oil at high concentration has been found to have poor oil removal efficiency and agglomeration using only a polymer flocculant An oil-containing wastewater treatment system with the following new configuration utilizing the reaction was tried.

  A cationic polymer flocculant with a high degree of polymerization produces scum (oil-containing scum) from oil-containing wastewater, and the floating scum is separated, dehydrated and deoiled to collect solids (cake), and after scum separation The liquid component is further subjected to a normal coagulation reaction treatment and drained.

  In view of the above, the present invention provides a novel oil-containing wastewater treatment apparatus that contains oil at a high concentration and is suitable for treating oil-in-water (O / W) emulsion wastewater through a coagulation reaction treatment. The purpose (issue) is to do.

  The oil-containing wastewater treatment apparatus of the present invention has the following configuration.

An apparatus for treating O / W emulsion oil-containing wastewater containing oil at a high concentration,
One or two or more stages of agglomeration reaction tanks capable of reacting and producing an oil-containing scum capable of being fed using only a cationic polymer flocculant, and an oil-containing scum floated and separated from the slurry containing the oil-containing scum A scum floating separation tank provided with a means for collecting and collecting the scum, and a scum muddy tank provided with means for crushing the collected oil-containing scum and making it muddy so that it can be transported.

  By using a cationic polymer flocculant, the generation of oil-containing scum of oil-containing wastewater is promoted, the scum oil-containing slurry generated in the flocculation reaction tank is floated and collected, and further, the collected oil-containing scum is crushed. By arranging each device, it becomes easy to transfer and post-process (dehydration and deoiling) of the scum which is a rubber-like elastic jelly body.

  The agglomeration reaction tank comprises two or more reaction baths capable of two-stage treatment of the pre-stage coagulation reaction and the post-stage coagulation reaction, and the reaction bath for the pre-stage coagulation reaction is equipped with a stirrer capable of generating a descending axial flow. It is desirable that the final reaction bath has a stirrer capable of generating an upward axial flow.

  The slurry containing the floating floc aggregate (scum) generated in the first stage agglomeration reaction (scum-containing slurry) is transferred to the final reaction bath for the second stage agglomeration reaction, and the ascending axial flow is applied to further increase the scum. While suppressing the coarsening (growth), the aggregation reaction can be terminated, and the scum-containing slurry can be overflowed and dropped from the final reaction bath, so that the slurry can be discharged smoothly. That is, the slurry-like liquid can be easily transferred to the next step such as a solid-liquid separation step.

The scum flotation separation tank is a vertically opened cylindrical body connected to a separation tank main body into which scum-containing slurry is introduced, and a slurry introduction pipe arranged at the center of the separation tank for introducing the scum-containing slurry from the side surface. The slurry introduction chamber, the clarified water discharge means connected to the clarified water outlet arranged at a position lower than the upper opening of the slurry introduction chamber, and the clarified water discharge means connected to a position higher than the upper opening of the slurry introduction chamber A scum collecting means for scraping and collecting the scum, and the clarified water discharging means is connected to the clarified water lead-out port and the other end opening (overflow port) has a height of the water surface of the separation tank. A communication pipe in a position to regulate the water, and a clear water discharge chamber for receiving the overflow water of the communication pipe,
It is desirable to have a configuration.

  By introducing the slurry from the side wall into the slurry introduction chamber of the cylindrical body, the floating component (scum) of the introduction slurry is guided mainly upward, spreads radially from the upper opening of the slurry introduction chamber, and floats on the water surface. The sedimentation component (sludge) is mainly guided downward, spreads radially from the lower opening of the slurry introduction chamber, and settles downward.

  Here, since the slurry is dispersed through the slurry introduction chamber, disturbance due to the slurry introduction flow of the levitation / sediment component hardly occurs, and levitation separation or sedimentation separation is also promoted.

  Similarly, since the clarified water discharging means overflows from the middle of the separation tank to the clarified water discharge chamber disposed outside the separation tank through the communication pipe, the clarified water derivation flow of the settling and floating components in the separation tank It is difficult to cause sedimentation and levitation disturbance due to, and levitation separation or sedimentation separation is also promoted.

  If the clarified water outlet is higher than the upper opening height of the slurry introduction chamber, the floating component (scum) may be sucked into the clarified water outlet flow.

  The oil-containing wastewater treatment apparatus having the above-described configuration further includes a scum storage tank provided with means for collecting and collecting the sludge-aggregated aggregated scum and intermittently stirring to float and separate the oil. Is desirable.

  Since the oil-containing scum contains a high-concentration oil component due to the scum storage tank, the oil recovery efficiency can be increased by retaining the oil-containing scum for a certain period of time. That is, the scum cut by the scum muddying device is polymerized again and becomes rubbery. At this time, the wrapping action of the oil is reduced, and the recovered oil is oozed out to the upper part of the mud scum. By recovering this floating oil component with a recovery pump or the like, reusable oil component can be recovered and the processing efficiency of the dehydration process (solid-liquid separation) in the next step can be increased.

  Furthermore, an oil-water separation tank is provided that separates and recovers the oil in the desorbed liquid generated by the dehydration treatment of the primary separation sludge scum (coagulated scum) obtained by floating and separating the oil in the scum storage tank. It is desirable.

  By providing the oil / water separation tank, the oil recovery efficiency can be further increased, and the outflow of the oil to the outside of the system can be further reduced.

  First, an embodiment of the oil-containing wastewater treatment apparatus (system) of the present invention will be described with reference to FIG. 1 showing a flowchart (flow diagram).

  The case where it applies to the flowchart (flow chart) of description (plant) based on the oil-containing wastewater treatment apparatus (system) of this invention is demonstrated. Here, a continuous operation will be described as an example, but an intermittent batch (batch) operation is also possible.

  In this equipment (system), processing oil-in-water (O / W) emulsion (emulsion) containing oil in high concentration (usually about 1000 mg / L or more, preferably 5000-15000 mg / L). Assuming

  Examples of oil-containing wastewater include industrial wastes from which printing presses and machine oils have been wiped off, and laundry wastewater from work gloves and work clothes.

  The oil-containing wastewater treatment apparatus of this embodiment is basically capable of treating one or more stages in which oil-containing scum (flocculated scum) that can be fed using only a cationic polymer flocculant is produced by reaction. Agglomeration reaction tank 12, scum flotation separation tank 14 equipped with means for collecting and collecting oil-impregnated scum floated and separated from the slurry containing oil-impregnated scum, and crushing the collected oil-impregnated scum and making it muddy for transfer And a scum muddy tank 16 having means for carrying out the above.

  Here, the cationic polymer flocculant is used because the waste liquid of the above-mentioned O / W emulsion is usually kept neutral or weakly alkaline (pH is about 7 or more). They are negatively charged and repel each other and stabilized. For this reason, aggregation is accelerated | stimulated by using what contains a large amount of cations (cations) in one molecule electrically.

  Particularly, among the cationic polymer flocculants, those having a high degree of polymerization (usually 5 million or more, desirably 6 million or more) are desirable because they have a strong aggregating action on the O / W emulsion. Specific examples thereof include “Hyperclear C105” (manufactured by Shinto Blator Co., Ltd., degree of polymerization: about 7.5 million).

  The present embodiment further includes a scum storage tank 18 provided with a means for storing mudified scum (oil-containing scum) and intermittently stirring to float and separate the oil component, and further, a scum storage tank. 18 is provided with an oil / water separation tank 22 for separating and collecting the oil in the desorbed liquid generated by the dewatering process (dehydrator) 20 of the primary separated sludge scum from which the oil has been floated and separated.

  Although not necessarily, the scum separation residual liquid generated from the scum flotation separation tank (primary) is subjected to a series of secondary treatments via the neutralization tank 24, the secondary agglomeration reaction tank 26, and the pressurized flotation separation tank 28. Is applied to the sewage system (drainage).

  The dewatered scum (cake) generated in the dehydrator 20 is disposed of through the dryer 30.

  Next, the main tanks and devices will be described in detail.

(1) (Primary) agglomeration reaction tank 12:
The cationic polymer flocculant used here has a high degree of polymerization and a high viscosity. Therefore, strong stirring is required for well stirring with wastewater containing a high concentration of oil. In addition, the addition method of the flocculant is less if it is added in about three times than when it is added all at once. Further, the floc obtained from this agglomeration reaction encloses a high-concentration oil component, so it has a low specific gravity and easily floats in the reaction tank (bath). Since a polymer flocculant having a high degree of polymerization is used, a large lump of rubber elastic jelly is formed in the reaction tank, so that it stays in the dead space depending on the surface shape of the reaction tank. For this reason, it is necessary to construct a baffle plate. In some cases, it is necessary to generate an ascending axial flow rather than a descending axial flow in the direction of stirring in each bath. These devices facilitate the transfer of the aggregate liquid to the next tank.

  More specifically, for example, the following configuration is used (see FIG. 2).

  Note that raw water can be quantitatively supplied to the primary agglomeration reaction tank 12 continuously or intermittently by a pump (not shown) through the screen 11.

  In the present embodiment, there are three bath configurations of a preliminary reaction bath 34 and a main reaction bath 36 for the former stage agglomeration reaction and a final reaction bath 38 for the latter stage agglomeration reaction.

  In this embodiment, a flocculant can be supplied to each reaction bath 34, 36, 38 from a flocculant tank (not shown).

  Here, each reaction bath 34, 36, 38 is linearly connected with a substantially rectangular (including a square) cross section.

  Each reaction bath 34, 36, 38 is equipped with a stirrer 39 provided with a propeller-type stirring blade 40 a in multiple stages (two stages in the figure) on a stirring shaft (rotating shaft) 39 b. This is from the viewpoint of good stirring efficiency and water flow (downward or upward axial flow) formation. Although not inevitable, the prime mover M in each stirrer 40 is capable of rotating speed adjustment and forward / reverse rotation.

  In addition, the liquid outlets 34a and 36a of the reaction baths 34, 36, and 38 are formed so as to be sequentially lowered from the front stage side to the rear stage side, and liquid transfer between the reaction baths 34, 36, and 38 is possible using the head difference. It is said that.

  Further, the capacity of each tank is not necessarily the same. For example, it is possible to make the preliminary / main reaction bath for the pre-stage flocculation reaction small and the large final reaction bath for the post-coagulation reaction. is there.

  The main reaction bath 36 and the final reaction bath 38 include corner cut members (rectifying members) 42 in addition to the liquid inlets (respectively, the preliminary reaction bath 34 and the outlet of the main reaction bath 36) 34a, 36a and the liquid outlets 36a, 38a. ing. In this embodiment, in both reaction baths 36 and 38, the corner cut member 42 is an inverted triangular pyramid block having a right upper triangular shape having an inclined surface 42a that guides (rectifies) an axial flow in the upward central direction. It is arranged on the upper side (see FIG. 4). At this time, the height of the upper surface is higher than the height of the liquid outlets 36a and 38a of each tank.

  In addition, the reaction bath 66 has a liquid inlet 34a and a liquid outlet 36a arranged on a substantially diagonal line at the upper end, and a horizontal weir plate (baffle plate) 44 directly below the liquid outlet side. ing. Here, the size of the weir plate 44 is to prevent the scum from being destroyed when the upward flow of the axial flow moves to the final reaction bath 38 of the slurry. Moreover, the mounting position of the weir plate 44 is, for example, about 30 to 40 cm below the outlet height and above the uppermost stirring blade 40a.

  The final reaction bath 38 is provided with an overflow chamber 46 on the liquid outlet 38a side, and a processed material receiving port of the scum flotation separation device 14I via a slurry transfer pipe (not shown) due to its own weight falling from the overflow chamber 46. It is possible to connect.

(2) Scum levitation separation tank 14:
As described above, the oil-impregnated scum (aggregated floc) produced in the primary agglomeration reaction tank has a low specific gravity, so that the separation of scum and treated water does not depend on pressurized flotation and can be sufficiently solid-liquid separated by natural flotation. However, since the oil-impregnated scum (floc) becomes a large lump of rubber-like elastic jelly body, it is desirable to provide four or more skimmers (collected scum rakes) 66 that rotate and scrape the flocs to the recovery hopper. As a skimmer shape, a rake-like shape is good in both draining condition and recovery rate.

  Specifically, for example, the following configuration is used (see FIGS. 3 to 6).

  Basically, 1) a separation tank main body 48, 2) a slurry introduction chamber 50, 3) a clarified water discharge means 52 and 4) a scum recovery means 54, and 5) a sludge recovery means 56 are provided.

  1) The separation tank body 48 is charged with scum-containing slurry, and has a cylindrical shape in the illustrated example.

2) The slurry introduction chamber 50 is a vertically open cylindrical body that is disposed in the center of the separation tank body 48 and is connected to a slurry introduction pipe 58 that introduces scum-containing slurry from the side surface. Here, the cylindrical body forming the slurry introduction chamber 50 is a cylindrical body in the illustrated example, but may be a (positive) rectangular cylindrical body.
The installation position is the water surface height W. It is about 30 cm below L. Further, the joining position of the slurry introduction pipe 52 may be substantially the center height of the cylindrical body (slurry introduction chamber 50). In addition, the tip of the slurry introduction pipe 58 is slightly inclined upward for the purpose of floating separation in this embodiment.

  3) The clarified water discharge means 52 is connected to the clarified water outlet 60a disposed at a position lower than the upper opening of the slurry introduction chamber 50, and one end is connected to the clarified water outlet 60a and the other end opening ( Overflow port) 60b is the height of the separation tank water surface. A communication pipe 60 at a position where L is regulated and a clarified water discharge chamber 62 for receiving the overflow water of the communication pipe 60 are provided. The clarified water discharge chamber 62 is transferred to the secondary treatment step (secondary treatment apparatus) by the clarified water discharge pipe 64.

  In this embodiment, the sliding pipe 64 is attached to the other end opening 60a of the communication pipe 60 so that the vertical position can be adjusted, the height of the overflow port 57 can be moved, and the water level of the separation tank body 48 can be adjusted. is there.

  The scum collecting means 54 collects and collects the scum that is located at a position higher than the upper opening of the slurry introduction chamber 50, that is, above and floats, and a plurality of (in the illustrated example, eight) scum rakes ( A skimmer) 66 and a scum recovery hopper 68 for receiving the scraped scum. The collection hopper 68 includes an inclined scraping stage 70 that can be partially submerged in front of the side opening wall facing the collecting direction of the collecting scum rake 66. In the present embodiment, a discharge screw conveyor 72 is further provided on the bottom side of the collection hopper 68. The discharge port 72b of the discharge screw conveyor 72 is connected to the scum mud tank 16 via a transfer pipe (not shown) so that it can be transferred to the scum mud tank (crushing tank) 16 by dropping its own weight. .

  The position of the recovery hopper 68 is at a position (on the same diameter in the example) opposite to the position where the slurry introduction pipe 52 is attached, but is not particularly limited and may be any position.

  Further, it is desirable to arrange a lowering prevention rod 74 along the moving direction of the collecting scum rake 66 so that the collecting scum rake 66 moves smoothly on the opening surface of the collecting hopper 68 after the collecting scum rake 66 has been collected. .

  The collecting scum rake 66 includes a strip-shaped blade 76 made of a rigid material, and a support member 78 that holds the blade 76 in a direction facing the collecting surface. Specifically, the support member 78 and the blade 76 are supported via a plate-like elastic member 77 (for example, a rubber plate; a plate spring may be used).

  The cutting edge of the blade 76 has a shape in which cutout portions 76a and flat portions 76b are alternately formed. Specifically, the shape of the notch 76a is a triangle in the illustrated example, but it may be a semicircular shape, a trapezoidal shape, or a rectangular shape. The ratio (A: B) between the cutout portion 76a and the flat portion 76b is 1: 5 to 1:10, preferably 1: 6 to 1: 8. The blade 76 has an angle cross section for easy mounting (see FIG. 6).

  The number of the collection scum rakes 66 is 6 to 8, the size of the blade 76 is, for example, 6.5 to 8.5 cm in height, 1 to 2 cm in width of the notch 76a, and 12 in width of the flat portion 76b. ~ 18 cm is desirable.

  Moreover, as for the inclination angle of the scraping stage 70, (alpha): 6-7 degrees is desirable, for example.

  The support member 80 and the blade 76 may be detachable, and the number of blades 76 may be changed as appropriate according to the characteristics of the oil-containing wastewater.

  The sludge collecting means 56 in this embodiment scrapes and collects the sludge that has settled on the bottom plate of the separation tank main body 48. The sludge collecting chamber 80 is formed by projecting downward in the center, and the sludge collecting chamber 80. And a sludge rake 82 for scraping sludge inside. The sludge rake 82 is composed of, for example, a plurality of scraping blades attached obliquely at a predetermined angle to the lower surface of a horizontal rotating rod (support member).

  Here, the sludge collection chamber 80 is connected to the scum mud tank 16 through a sludge transfer pipe 84 provided with a sludge transfer pump (not shown).

(3) Scum muddy tank 16
Since the oil-impregnated scum (floc) produced in the present invention is a rubber elastic jelly body as described above, there is no appropriate pump for pumping it to the storage tank. For this reason, a device for chopping rubber elastic scum once to make it muddy is the muddy tank. The impeller shape (blade shape) of the stirrer uses turbine blades as shown in the upper impeller with the lower part being a normal propeller structure. As a result, there is no restriction on the transfer pump, and a transfer to a long distance of 10 m or more using a Roots type pump or the like is sufficiently possible.

  More specifically, for example, the following configuration is adopted.

  A muddy tank main body (stirring tank) 86, a stirrer 88 and a liquid level detector 90 assembled to the muddy tank main body 86 are provided. The mud tank 86 is usually a planar rectangle (square: including a square) or a polygon. If the stirrer 60 is set in the center when the plane shape is circular, the scum rotates together with the agitating blades and crushing blades described later, making it difficult to flow and crush the scum. In addition, although a baffle plate can also be appropriately arranged on the inner surface of the muddy tank, care must be taken because scum may stay depending on the mounting position of the baffle plate.

  The liquid level detector 90 is connected to a scum transfer pump (not shown) in a scum transfer pipe (not shown) connected to the bottom side wall of the muddy tank body 86 and a stirrer (prime motor M) 92 by signal wiring. It is possible.

  And the stirrer 88 is equipped with the stirring blade 88b and the crushing blade | wing 89 on the rotating shaft (stirring shaft) 88a, respectively one each up and down.

  The crushing blade 88c is provided with crushing teeth 89a and 89b alternately projecting up and down around the periphery.

(4) Scum storage tank 18:
During operation of the levitation separator, the storage scum is intermittently stirred and mixed by the stirring device at regular intervals from the recovered scum muddying device. However, if the stirring time is too long, repolymerization is not promoted, so the stirring time is 1 to 5 minutes as an example, and it is stopped for 29 to 25 minutes. The oil from the repolymerized rubber-like scum is collected once a day by a floating oil recovery pump before the floating separator is in operation.

  More specifically, for example, the following configuration is used (FIG. 8).

  A storage tank main body 92, a stirrer 94 assembled to the storage tank main body 92, a liquid level detector 96, and an oil recovery pump 98 are provided.

  The liquid level detector 96 can be connected to the oil recovery pump 98 by signal wiring.

  And the stirrer 94 is equipped with the stirring blade 95 up and down on the rotating shaft (stirring shaft) 94a. As shown in FIG. 8 (B) of the stirring blade (impeller) 95, it is desirable to use a flat trapezoidal shape curved downwards as a blade element. Specifically, “TAKEUTCHI T-A3 impeller” (manufactured by Takeuchi Seisakusho Co., Ltd.) and the like can be suitably used. The stirring blade can uniformly mix rubber-like scum having a very high viscosity in a short time. Here, the number of the wing elements 95a is three, but may be four or more.

  The oil recovery pump 98 can be adjusted in height by the winch 100 driven by a signal from the liquid level detector 96.

  The connection hose of the oil recovery pump 98 is connected to the oil recovery tank, although not shown. The residual scum after oil separation in the scum storage tank can be conveyed to the dehydrator 20 via a scum transfer pipe provided with a pump.

  At this time, the dehydrator 20 is not particularly limited (for example, a precoat method), but is preferably a screw press type dehydrator that does not clog the filtration surface even if oil is contained.

(5) Oil / water separation tank 32
The rubber elastic scum is dehydrated by a dehydrator 20 such as a screw press. In addition to moisture, oil that still remains in the rubber elastic scum is mixed into the desorbed liquid during dehydration. Since the oil and water separation tank easily separates the water and the oil, the oil can be further recovered by once recovering the desorbed liquid.

  More specifically, for example, the configuration shown below (FIG. 9).

  Separation tank main body 102, overflow liquid inlet chamber 104 at the center of the separation tank main body 102, and overflow port 106 for overflowing floating oil (upper layer liquid) O and introducing it into an oil recovery tank (not shown). And a lower layer liquid outlet 108 for discharging the lower layer liquid (water) W. Naturally, the desorbed liquid introducing chamber 104 is connected to a desorbed liquid introducing pipe connected to the dehydrator 20. Reference numeral 105 denotes a desorption liquid introduction chamber holding bracket.

Next, using the oil-containing wastewater treatment apparatus (system) of the above embodiment, the wastewater (O / W emulsion) having the indicated water quality is used as raw water, and the operation is performed using the indicated cationic polymer flocculant (throughput 40 m). Table 1 shows the results of water quality analysis conducted for ³ / h).

  In the conventional method, the waste water after breaking the emulsion into sulfuric acid and neutralizing the waste water that has become more acidic with caustic soda, aggregating with an anionic polymer flocculant, and further clarifying by pressure flotation separation is used. is there.

  It turns out that the water quality equivalent to the past is obtained. Further, in the case of this oil-containing wastewater treatment apparatus, the amount of generated sludge was much smaller.

  In addition, the meaning of each abbreviation in Table 1 is as follows.

SS (Suspension Solid): suspended solid amount COD (Chemical Oxygen Demand): chemical oxygen demand BOD (Biochemical Oxygen Demand): biochemical oxygen demand n-Hex (n-Hexane Extract): n-hexane extract quantity

It is a flow sheet (flow diagram) showing an example of the oil-containing wastewater treatment apparatus of the present invention. (A), (B) is a model longitudinal cross-sectional view and model top view which respectively show an example of the (primary) agglomeration reaction tank used for the oil-containing wastewater treatment apparatus of this invention. It is a model longitudinal cross-sectional view which shows an example of the scum flotation separation tank used for the oil-containing wastewater treatment apparatus of this invention. Similarly, it is a model plan view. It is model sectional drawing which similarly shows the detail of a scum collection | recovery means. FIG. 5 is a detailed view of blades in the scum rake of the scum recovery means. (A), (B) is the model longitudinal cross-sectional view which shows an example of the scum mudification tank used for the oil-containing wastewater treatment apparatus of this invention, respectively, and the front and top view of a crushing blade | wing. (A), (B) is a model longitudinal cross-sectional view which shows an example of the scum storage tank used for the oil-containing wastewater treatment apparatus of this invention, respectively, and the top view of a stirring blade. It is model sectional drawing of the oil-water separation tank used for the oil-containing wastewater treatment apparatus of this invention.

Explanation of symbols

12 (Primary) Coagulation Reaction Tank 14 Scum Levitation Separation Tank 16 Scum Muddy Tank 18 Scum Separation Tank 22 Oil Water Separation Tank

Claims (4)

An apparatus for treating oil-containing wastewater that contains oil at a high concentration and is an oil-in-water (O / W) emulsion,
One or two or more stages of agglomeration reaction tanks capable of reacting and producing liquid-containing oil-containing scum using only a cationic polymer flocculant, and oil-containing scum floated and separated from the slurry containing the oil-containing scum A scum flotation separation tank provided with a means for collecting and collecting the scum, and a scum muddy tank provided with a means for crushing the collected oil-containing scum and making it muddy so that it can be transported,
The agglomeration reaction tank is composed of two or more reaction baths capable of two-stage treatment of the pre-stage coagulation reaction and the post-stage coagulation reaction, and the reaction bath for the pre-stage coagulation reaction is equipped with a stirrer capable of generating a descending axial flow. An oil- containing wastewater treatment apparatus characterized in that the final reaction bath is equipped with a stirrer capable of generating an upward axial flow. An apparatus for treating oil-containing wastewater that contains oil at a high concentration and is an oil-in-water (O / W) emulsion,
One or two or more stages of agglomeration reaction tanks capable of reacting and producing an oil-containing scum capable of being fed using only a cationic polymer flocculant, and an oil-containing scum floated and separated from the slurry containing the oil-containing scum A scum flotation separation tank having means for collecting and collecting the scum, and a scum muddy tank having means for crushing the collected oil-containing scum and making it muddy so that it can be transported.
The scum flotation separation tank is
A separation tank body into which the scum-containing slurry is charged;
A slurry introduction chamber of an upper and lower opening cylindrical body, which is disposed in a central portion of the separation tank and connected to a slurry introduction pipe for introducing scum-containing slurry from a side surface;
Clarified water discharge means connected to the clarified water outlet arranged at a position lower than the upper opening of the slurry introduction chamber;
A scum recovery means for scraping and recovering the scum that has been levitated and disposed above the upper opening of the slurry introduction chamber, and
The clarified water discharging means includes a communication pipe having one end connected to the clarified water outlet and a height of the other end opening (overflow port) regulating the water surface height of the separation tank, and an overflow of the communication pipe. A clear water discharge chamber for receiving running water,
An oil- containing wastewater treatment apparatus characterized by that. The oil-containing wastewater according to claim 1 or 2 , further comprising a scum storage tank having a means for storing the muddy scum and intermittently stirring to float and separate the oil component. Processing equipment. Furthermore, claims, characterized in that it comprises an oil-water separation tank for recovering separated oil content of desorption solution generated by the dehydration treatment of the primary separation mud Joka scum obtained by flotation of oil in the scum storage tank 3. The oil-containing wastewater treatment apparatus according to 3 .

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