CN115925151A - A method for harmless treatment of acidified oily wastewater - Google Patents

Abstract

The invention relates to a harmless treatment method of acidified oil wastewater, which comprises the following steps: 1) Introducing the acidified oil wastewater into a high-concentration sulfate removal device, adding quicklime for reaction, removing high-concentration sulfate in the wastewater, and adjusting the pH value of the wastewater; 2) Separating the waste water slag water from which the sulfate is removed to obtain a separation liquid, and introducing the separation liquid into the COD (chemical oxygen demand) cutting device through a water distribution well; 3) Sequentially adding iron-free aluminum sulfate and polyacrylamide into the separation liquid for reaction, and agglomerating, flocculating and precipitating the separation liquid; 4) Introducing the wastewater with reduced COD into a biochemical treatment system, and sequentially utilizing an ozone reaction tank and A ² Performing advanced treatment on the O reaction tank; 5) And introducing the wastewater after the biochemical treatment into a sedimentation tank for secondary sedimentation to obtain harmless wastewater. The method can be used for harmlessly treating high-concentration sulfate, COD and phosphate in the acidified oil wastewater with high efficiency and low cost, and can ensure that the acidified oil wastewater reaches the national discharge standard.

Description

A method for harmless treatment of acidified oily wastewater

technical field

The invention belongs to the technical field of treatment of acidified oily wastewater, in particular to a harmless treatment method for acidified oily wastewater.

Background technique

In recent years, the application of reprocessing the waste from oil production to produce chemical raw materials is increasing, and plant acidified oil can be used as an important production raw material for daily chemicals. In the production process, a large amount of high-concentration organic matter and high-concentration sulfuric acid must be produced at the same time. Salt wastewater, in which most organic substances are artificially synthesized, is difficult to degrade naturally in nature. Among the pollutants discharged into the wastewater, there are many substances in their own bodies or the small molecular substances generated by degradation that have great carcinogenic or mutagenic effects. If these wastewaters are directly discharged into nature, it will cause serious damage to the environment. Very toxic pollution.

Due to the high concentration of sulfate, high concentration of COD, strong acidity, high concentration of phosphate, poor biodegradability and other characteristics of acidified oily wastewater, ordinary sewage treatment processes cannot be treated until it reaches the national discharge standard. At the same time, the existing acidified oil treatment process has not really achieved low power consumption, low cost, high-efficiency and rapid removal of high-concentration sulfate, COD and phosphate in wastewater.

Therefore, in view of the current specific wastewater treatment problems of acidified oil production enterprises, it is urgent to develop a high-efficiency, low-cost acidified oil harmless treatment method to solve the above existing problems.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention provides a method for harmless treatment of acidified oily wastewater, which can be used for high-efficiency, low-cost harmless treatment of high-concentration sulfate, COD and phosphate in acidified oily wastewater, and the method treats The acidified oily wastewater can meet the national discharge standards.

In order to achieve the above object, technical scheme of the present invention is:

A method for the harmless treatment of acidified oily wastewater. The acidified oily wastewater is pretreated and then subjected to advanced treatment. The specific treatment method includes the following steps:

1) Pass the acidified oily wastewater into the high-concentration sulfate removal device, and add quicklime to the device for reaction, remove the high-concentration sulfate in the wastewater, and adjust the pH value of the wastewater to 6-9 to obtain sulfuric acid removal Salt wastewater;

2) Slag-water separation of the sulfate-removed wastewater to obtain a separation liquid, and pass the separation liquid into the COD reduction device through a water distribution well;

3) Fe-free aluminum sulfate and polyacrylamide are sequentially added to the COD reduction device to react with the separation liquid, so that the separation liquid agglomerates, flocculates, and precipitates to obtain COD-reduced wastewater;

4) Pass the COD-reduced wastewater into the biochemical treatment system, and use the ozone reaction tank and A ² O reaction pool to conduct advanced treatment on the COD-reduced wastewater to obtain biochemically treated wastewater;

5) Pass the biochemically treated wastewater into a sedimentation tank for secondary precipitation, and then separate slag and water to obtain harmless wastewater.

Preferably, in the step 1), quicklime is added at a ratio of 29 g per liter of acidified oily wastewater; the reaction time between the acidified oily wastewater and quicklime is 5 minutes.

Preferably, said step 3) specifically includes the following steps:

31) Add iron-free aluminum sulfate according to the ratio of 2.1-3g per liter of separation liquid, and stir for 5-8min, so that the organic matter in the separation liquid can quickly agglomerate and flocculate;

32) Add polyacrylamide at a ratio of 15-19mg per liter of separation liquid after flocculation occurs, and let it stand for 30-60 minutes, so that the flocculation and flocculation can quickly flocculate and settle to the bottom of the COD reduction device to reduce COD COD wastewater.

Preferably, said step 4) specifically includes the following steps:

41) Pass the COD-reduced waste water into the ozone reaction tank, and cast ozone for oxidative decolorization, reduce the remaining COD contained in it, and decompose its macromolecular pollutants into small molecular pollutants to obtain oxidative decolorized waste water;

42) Pass the oxidatively decolorized wastewater into the A ² O reaction pool, and remove phosphate and ammonia nitrogen components in the wastewater through anaerobic, anoxic, and aerobic biochemical treatments to obtain biochemically treated wastewater.

Preferably, in the step 5), the SO ₄ ^2- value in the harmless wastewater is 110mg/L-189mg/L, and the removal rate is 84.91%-91.02%.

Preferably, in the step 5), the TP value in the harmless waste water is 0.3mg/L-0.5mg/L, and its removal rate is 99.8%-99.81%.

Preferably, in the step 5), the COD value in the harmless waste water is 35 mg/L, and its removal rate is 99.90%-99.95%.

Technical effect and advantage of the present invention:

1. A method for the harmless treatment of acidified oily wastewater provided by the present invention. The acidified oily wastewater is reacted by adding quicklime to remove high-concentration sulfate and adjust the pH value, and to separate slag and water to obtain a separation liquid; then Then add iron-free aluminum sulfate and polyacrylamide to react with the separation liquid in order to make the separation liquid agglomerate, flocculate and precipitate to obtain COD-reduced wastewater; finally, pass the COD-reduced wastewater into the biochemical treatment system for advanced treatment to obtain Biochemically treated wastewater, and the biochemically treated wastewater is subjected to secondary precipitation and slag-water separation to obtain harmless wastewater, which can be used for high-efficiency and low-cost harmless treatment of high-concentration sulfate, COD and Phosphate can make the acidified oily wastewater meet the national discharge standard. Therefore, the acidified oily wastewater treatment method has great promotion and application value.

2. In the harmless treatment method of acidified oily wastewater provided by the present invention, in the pretreatment stage, the addition of quicklime with low cost and no other by-products, and iron-free aluminum sulfate and polyacrylamide with low cost and high efficiency, It can remove high-concentration sulfate and part of COD in wastewater, and can also regulate the pH of wastewater. Its process for treating acidified oily wastewater is low in cost, good in effect, and fast in efficiency, and can effectively decompress the subsequent biochemical treatment stage. .

Description of drawings

Fig. 1 is the treatment effect figure of the present invention to remove SO ₄ ^2- in acidified oily wastewater;

Fig. 2 is the treatment effect figure of the present invention to remove COD in the acidified oily wastewater;

Fig. 3 is the treatment effect diagram of the present invention to remove TP in the acidified oily wastewater;

Fig. 4 is the structural representation of the high concentration sulfate removal device that the present invention uses;

Fig. 5 is a schematic structural view of the COD reduction device used in the present invention.

Numbers in the figure: 1. High-concentration sulfate removal device; 101. Shell of sulfate removal device; 102. First overflow buffer plate; 103. Preliminary neutralization reaction chamber; 104. Deep neutralization reaction chamber; 105. Acidification Oily wastewater inlet pipe; 106, first outlet; 107, second outlet; 108, neutralizer inlet; 109, drainage valve; 110, semicircular plate; 111, conical plate; 2, COD Reduction device; 201, COD reduction device housing; 202, second overflow buffer plate; 203, agglomeration flocculation chamber; 204, secondary sedimentation chamber; 205, stirring device; 2051, stirring rod; 2052, stirring blade; 206 , water inlet pipe for clumping agent; 207, water inlet pipe for flocculant; 208, discharge port for floc; 209, water inlet pipe for separation liquid; 210, water outlet; 211, discharge pipe for floc; 212, shell cover plate; , Inlet control valve.

Detailed ways

The present invention is described in further detail below in conjunction with the embodiment that accompanying drawing provides.

A method for the harmless treatment of acidified oily wastewater. The acidified oily wastewater is pretreated and then subjected to advanced treatment. The specific treatment method includes the following steps:

1) Pass the acidified oily wastewater into the high-concentration sulfate removal device, and add quicklime to the device for reaction, remove the high-concentration sulfate in the wastewater, and adjust the pH value of the wastewater to 6-9 to obtain sulfuric acid removal Salt wastewater. Further, in order to ensure the pH value required for the subsequent treatment of the acidified oily wastewater, an appropriate amount of quicklime can be added again, and the reaction is sufficient for 5 minutes.

During specific implementation, the quicklime is added at a ratio of 29g per liter of acidified oily waste water.

During specific implementation, the reaction time of the acidified oily waste water and quicklime is 5 minutes.

2) Slag-water separation of the sulfate-removed wastewater to obtain a separation liquid, and pass the separation liquid into the COD reduction device through a water distribution well.

3) Add iron-free aluminum sulfate and polyacrylamide to the COD reduction device in sequence to react with the separation liquid, so that the separation liquid is agglomerated, flocculated, and precipitated to obtain COD-reduced wastewater. Specifically, the following steps are included:

31) Add iron-free aluminum sulfate according to the ratio of 2.1-3g per liter of separation liquid, and stir for 5-8min, so that the organic matter in the separation liquid can quickly agglomerate and flocculate;

32) Add polyacrylamide at a ratio of 15-19mg per liter of separation liquid after flocculation occurs, and let it stand for 30-60 minutes, so that the flocculation and flocculation can quickly flocculate and settle to the bottom of the COD reduction device to reduce COD COD wastewater.

4) Pass the COD-reduced wastewater into the biochemical treatment system, sequentially use the ozone reaction tank and the ^A2O reaction tank to conduct advanced treatment on the COD-reduced wastewater to obtain biochemically treated wastewater, specifically including the following steps:

41) Pass the COD-reduced waste water into the ozone reaction tank, and cast ozone for oxidative decolorization, reduce the remaining COD contained in it, and decompose its macromolecular pollutants into small molecular pollutants to obtain oxidative decolorized waste water;

42) Pass the oxidatively decolorized wastewater into the A ² O reaction tank, and remove phosphate and ammonia nitrogen components in the wastewater through anaerobic, anoxic, and aerobic biochemical treatments to obtain biochemically treated wastewater.

5) Pass the biochemically treated wastewater into a sedimentation tank for secondary precipitation, and then separate slag and water to obtain harmless wastewater.

During specific implementation, the SO ₄ ^2- value in the harmless wastewater is 110 mg/L-189 mg/L, and the removal rate is 84.91%-91.02%.

During specific implementation, the TP value in the harmless wastewater is 0.3mg/L-0.5mg/L, and its removal rate is 99.8%-99.81%.

During specific implementation, the COD value in the harmless wastewater is 35 mg/L, and its removal rate is 99.90%-99.95%.

In this implementation, steps 1), 2), and 3) are the pretreatment stages of acidified oily wastewater. In this stage, quicklime with low cost and no other by-products is used as the first step of the pretreatment stage, and the addition cost is low and the efficiency is high. A certain proportion of iron-free aluminum sulfate and polyacrylamide are carried out in the COD reduction device. The purpose is to remove the high concentration of sulfate and part of COD in the acidified oily wastewater, and at the same time, it can also play a role in regulating the pH of the acidified oily wastewater, and reduce the pressure for the subsequent biochemical treatment stage. At this stage, the SS removal rate of acidified oily wastewater is as high as 90%, the removal rate of sulfate is 90%, the pH value can be adjusted from 2 to 6-9 in the original acidified oily wastewater, and the biochemical property B/C≥0.5. It can fully meet the required conditions of subsequent biochemical treatment.

In this embodiment, step 4) is the advanced treatment stage of acidified oily wastewater. In this stage, through the ozone reaction tank in the biochemical reaction system, ozone is introduced to remove the remaining COD in the wastewater, and the turbidity and macromolecular compounds of the wastewater are degraded into The small molecule compounds enter the A ² O reaction pool of the biochemical treatment system, the first anaerobic pool, the main function of this pool is to release phosphorus, so that the concentration of P in the sewage increases, and the dissolved organic matter is absorbed by the microbial cells to make the waste water In addition, part of the ammonia nitrogen is removed due to the synthesis of cells, so that the concentration of ammonia nitrogen in the wastewater decreases. In the anoxic tank, the denitrifying bacteria use the organic matter in the wastewater as a carbon source, and the reflux mixture contains A large amount of NO ₃ -N is injected and NO ₃ -N is reduced to N and released to the air, so the concentration of BOD decreases, the concentration of NO ₃ -N decreases greatly, and the change of phosphorus is small. In the aerobic pond, the organic matter is biochemically degraded by microorganisms and continues to decrease; the organic nitrogen is ammonified and then nitrified, so that the concentration of NH ₃ -N decreases significantly, but the concentration of NO ₃ -N increases with the process of nitrification, and Р The excessive intake of phosphorus accumulating bacteria also decreased at a faster rate. Among them, the removal rate of COD, TP and other pollutants in wastewater is about 60%, and the removal rate of NH ₃ -N concentration is about 99%, thereby removing nitrogen and phosphorus in wastewater.

In this example, the acidified oily waste water passed into the high-concentration sulfate removal device is reacted by adding quicklime to remove high-concentration sulfate and adjust the pH value, and separate slag and water to obtain a separation liquid; then The separation liquid is passed into the COD reduction device, and then iron-free aluminum sulfate and polyacrylamide are added in sequence to react with the separation liquid, so that the separation liquid is agglomerated, flocculated, and precipitated to obtain COD-reduced wastewater; finally, the COD-reduced wastewater is passed into Advanced treatment is carried out in the biochemical treatment system to obtain biochemically treated wastewater, and the biochemically treated wastewater is subjected to secondary precipitation and slag-water separation to obtain harmless wastewater, which can be used for high-efficiency and low-cost harmless treatment acidification The high concentration of sulfate, COD and phosphate in the oily wastewater can make the acidified oily wastewater meet the national discharge standard. Therefore, the acidified oily wastewater treatment method has great promotion and application value.

Example 1

The acidified oily wastewater of an acidified oily wastewater treatment plant has a pH value of 1.9, a COD concentration of 74230 mg/L, a SO ₄ ^2- value of 839 mg/L, and a TP value of 302 mg/L.

Put the acidified oil wastewater into the high-concentration sulfate removal device, and add quicklime at a rate of 29g per liter of acidified oil wastewater, and make it react for 5 minutes. At this time, the pH value in the wastewater is 6, In order to ensure the pH required for subsequent treatment, add an appropriate amount of quicklime and react for 5 minutes. At this time, the pH value in the wastewater is 8; then separate the slag from water to obtain a separation liquid, and then pass the separation liquid through the water distribution well. In the COD reduction device, iron-free aluminum sulfate is added to the separation liquid at a ratio of 3g per liter of separation liquid, and stirred for 5 minutes to make the organic matter in the separation liquid quickly agglomerate and flocculate; Add polyacrylamide at a ratio of 19 mg, and let it stand for 30 minutes to quickly flocculate and precipitate the organic matter agglomerated and flocculated in the separation liquid to the bottom of the COD reduction device to obtain COD-reduced wastewater; pass the COD-reduced wastewater into the ozone reaction tank Inside, and put in enhanced oxidizing ozone for oxidative decolorization, reduce the remaining COD contained in it, and decompose its macromolecular pollutants into small molecular pollutants to obtain oxidative decolorized wastewater; pass the oxidative decolorized wastewater into A ² O reaction tank, and through anaerobic, anoxic, and aerobic biochemical treatment, the phosphate and ammonia nitrogen components in the wastewater are removed, and the biochemically treated wastewater is obtained; the biochemically treated wastewater is passed into the sedimentation tank for secondary Second precipitation, and then separation of slag and water to obtain harmless wastewater.

In this example, the SO ₄ ^2- value of the obtained harmless wastewater is 189 mg/L, and its removal rate is 91.02%; the TP value is 0.3 mg/L, and its removal rate is 99.81%; the COD value is 35 mg/L , and its removal rate is 99.95%.

Example 2

The acidified oily wastewater of an acidified oily wastewater treatment plant has a pH value of 3.4, a COD concentration of 34230 mg/L, a SO ₄ ^2- value of 729 mg/L, and a TP value of 265 mg/L.

Put the acidified oil wastewater into the high-concentration sulfate removal device, and add quicklime at a rate of 29g per liter of acidified oil wastewater, and make it react for 5 minutes. At this time, the pH value in the wastewater is 8. In order to ensure the pH required for subsequent treatment, add an appropriate amount of quicklime and react for 5 minutes. At this time, the pH value in the wastewater is 9; then separate the slag from water to obtain a separation liquid, and then pass the separation liquid through the water distribution well In the COD reduction device, iron-free aluminum sulfate is added to the separation liquid at a ratio of 2.1g per liter of separation liquid, and stirred for 8 minutes, so that the organic matter in the separation liquid can quickly agglomerate and flocculate; Add polyacrylamide at a ratio of 15 mg, and let it stand for 60 minutes to quickly flocculate and precipitate the organic matter agglomerated and flocculated in the separation liquid to the bottom of the COD reduction device to obtain COD-reduced wastewater; pass the COD-reduced wastewater into ozone reaction In the tank, and put in enhanced oxidizing ozone for oxidative decolorization, reduce the remaining COD contained in it, and decompose its high molecular pollutants into small molecular pollutants to obtain oxidative decolorized wastewater; pass the oxidative decolorized wastewater into In the A ² O reaction pool, and through anaerobic, anoxic, and aerobic biochemical treatment, the phosphate and ammonia nitrogen components in the wastewater are removed to obtain the biochemically treated wastewater; the biochemically treated wastewater is passed into the sedimentation tank for further processing. Secondary precipitation, followed by slag-water separation to obtain harmless wastewater.

In this example, the SO ₄ ^2- value of the obtained harmless wastewater is 110 mg/L, and its removal rate is 84.91%; the TP value is 0.5 mg/L, and its removal rate is 99.8%; the COD value is 35 mg/L , and its removal rate is 99.90%.

Example 3

Referring to shown in Fig. 4, high-concentration sulfate removal device 1 comprises sulfate removal device housing 101, and the inner chamber of described sulfate removal device housing 101 is divided into preliminary neutralization reaction chamber by the first overflow buffer plate 102 103 and deep neutralization chamber 104. The top of the sulfate removal device housing 101 is provided with an acidified oil wastewater inlet pipe 105, the bottom is respectively provided with a first discharge port 106 and a second discharge port 107, and both sides are respectively provided with a neutralizer feed port 108 And drain valve 109. The acidified oil wastewater inlet pipe 105, the first discharge port 106 and the neutralizer feed port 108 are all communicated with the preliminary neutralization reaction chamber 103; the second discharge port 107 and the drain valve 109 are all connected to the deep neutralization The reaction chamber 104 communicates. The bottom of the inner cavity of the preliminary neutralization reaction chamber 103 is provided with a semicircular plate 110, and the circumscribed circle of the semicircular plate 110 is connected with the inner sidewall and the bottom surface of the preliminary neutralization reaction chamber 103 respectively; A discharge port 106 is arranged at the junction of the semicircular plate 110 and the bottom surface of the preliminary neutralization reaction chamber 103 . The bottom of the inner cavity of the depth neutralization reaction chamber 104 is provided with a conical plate 111, the outer circle of the conical plate 111 is in contact with the inner sidewall of the depth neutralization reaction chamber 104, and the cone point is connected with the bottom surface of the depth neutralization reaction chamber 104. Contiguous; the second outlet 107 is set at the junction of the conical point of the conical plate 111 and the depth center and the bottom surface of the reaction chamber 104 . The upper end of the first overflow buffer plate 102 is set as a turn-out edge, and the turn-out angle of the turn-out edge is 45°. There are multiple drain valves 109 , and the multiple drain valves 109 are sequentially arranged at intervals in the depth and outside the reaction chamber 104 from top to bottom.

When treating high-concentration sulfate in the acidified oily wastewater in this embodiment, the acidified oily wastewater flows into the preliminary neutralization reaction chamber 103 through the acidified oily wastewater inlet pipe 105, and the acidified oily wastewater is mixed with the neutralizer feed port 108 under the action of gravity. The incoming quicklime undergoes a neutralization reaction. After the initial neutralization reaction chamber 103 is full, reduce the influent flow and velocity of the acidified oily wastewater, so that the waste water mixture flows into the deep neutralization reaction chamber 104 through the first overflow buffer plate 102, and the waste water mixture is carried out under the action of gravity. The deep neutralization reaction makes the secondary precipitation and separation can effectively ensure the removal effect of high-concentration sulfate. At the same time, the deep neutralization reaction can be carried out to improve the utilization rate of the neutralizer and reduce the cost. After the neutralization reaction is completed, the first discharge port 106 is opened to discharge the precipitate in the preliminary neutralization reaction chamber 103, and the separation liquid separated from the precipitation in the deep neutralization reaction chamber 104 is passed into the COD reduction device through the drain valve 109, and the separated The precipitate is discharged through the second outlet 107.

Example 4

Referring to FIG. 5 , the COD reduction device 2 includes a COD reduction device housing 1 , and a second overflow buffer plate 2 is provided in the inner cavity of the COD reduction device housing 1 . The second overflow buffer plate 2 divides the inner chamber of the housing 1 into an agglomeration flocculation chamber 3 and a secondary sedimentation chamber 4 , and the secondary sedimentation chamber 4 is located outside the agglomeration flocculation chamber 3 . The clumping and flocculation chamber 3 is provided with a stirring device 5 . The stirring device 5 includes a stirring rod 51 and a stirring blade 52 fixedly connected to one end of the stirring rod 51 . One end of the stirring rod 51 connected with the stirring blade 52 is located in the agglomeration flocculation chamber 3 , and the other end protrudes through the stirring port and is exposed on the top of the housing cover plate 12 . The clumping agent inlet pipe 6 and the flocculant inlet pipe 7 are arranged on the top of the agglomeration and flocculation chamber 3 , and the floc discharge port 8 and the separation liquid inlet pipe 9 are arranged on the bottom. A drain port 10 is provided on one side of the upper end of the secondary sedimentation chamber 4, and a floc discharge pipe 11 is provided on the opposite side of the lower end. The top of the COD reduction device housing 1 is provided with a housing cover plate 12 . The housing cover plate 12 is respectively provided with a clumping agent water inlet pipe installation hole, a flocculant water inlet pipe installation hole and a stirring port. The stirring port is opened at the center of the housing cover plate 12 . The installation hole of the water inlet pipe for the clumping agent and the installation hole for the water inlet pipe of the flocculant are respectively located at the side of the stirring port. One end of the agglomerating agent inlet pipe 6 and the flocculant inlet pipe 7 extends into the agglomeration flocculation chamber 3 through the installation hole of the agglomerating agent inlet pipe and the flocculant inlet pipe installation hole respectively, and the other ends are respectively exposed to the casing above the cover plate 12. The ends of the clumping agent inlet pipe 6 and the flocculant inlet pipe 7 exposed above the shell cover plate 12 are sequentially provided with a drug control valve, a drug flow meter and a drug flow meter for convenient and accurate dosing of the agglomerating agent and flocculant. The bottom cross-section of the COD reduction device housing 1 is arc-shaped, and the floc discharge port 8 is set at the center of the bottom of the COD reduction device housing 1; one side of the floc discharge port 8 is provided with a water inlet , one end of the separation liquid inlet pipe 9 extends into the agglomeration and flocculation chamber 3 through the water inlet, and the other end is exposed outside the COD reduction device housing 1, and the water inlet control valve and the water inlet flow rate are sequentially arranged on it. Meter and water inlet flow meter are used to control the water inlet speed of waste water.

When this embodiment treats COD in acidified oily wastewater, the separation liquid flows into the clumping flocculation chamber 3 at a constant speed and quantitatively from the separation liquid inlet pipe 9; The water inlet pipe 6 and the flocculant water inlet pipe 7 add the agglomerating agent and flocculant at a constant speed and quantitatively according to the inflow of the separation liquid, and carry out speed-controlled stirring through the stirring rod 6, so that the separation liquid in the agglomeration and flocculation chamber 3 is quickly Agglomeration and flocculation; after the separation liquid in the agglomeration flocculation chamber 3 is full, reduce the inlet flow and flow rate of the separation liquid through the control valve of the water inlet, and at the same time adjust the dosage of the agglomeration agent and flocculant through the agent control valve Timing, so that the separation liquid flows into the secondary sedimentation chamber 4 through the outer flange of the second overflow buffer plate 2, and uses gravity to carry out secondary agglomeration and flocculation to improve the COD reduction rate, thereby effectively improving the COD reduction effect . After the secondary agglomeration and flocculation is completed, the COD-reduced wastewater enters the biochemical treatment system through the outlet 10, and the flocs are discharged from the floc discharge pipe 11. The flocs in the agglomeration and flocculation chamber 3 are discharged through the floc discharge port 8 .

The above is only the preferred embodiment of the present invention, it should be pointed out that for those skilled in the art, without departing from the inventive concept of the present invention, some modifications and improvements can also be made, and these all belong to the present invention. protection scope of the invention.

Claims (7)

1. A method for the harmless treatment of acidified oily waste water, characterized in that: after the acidified oily waste water is pretreated, then advanced treatment is carried out, and the specific treatment method comprises the following steps: 1) Pass the acidified oily wastewater into the high-concentration sulfate removal device, and add quicklime to the device for reaction, remove the high-concentration sulfate in the wastewater, and adjust the pH value of the wastewater to 6-9 to obtain sulfuric acid removal Salt wastewater; 2) Slag-water separation of the sulfate-removed wastewater to obtain a separation liquid, and pass the separation liquid into the COD reduction device through a water distribution well; 3) Fe-free aluminum sulfate and polyacrylamide are sequentially added to the COD reduction device to react with the separation liquid, so that the separation liquid agglomerates, flocculates, and precipitates to obtain COD-reduced wastewater; 4) Pass the COD-reduced wastewater into the biochemical treatment system, and use the ozone reaction tank and A ² O reaction pool to conduct advanced treatment on the COD-reduced wastewater to obtain biochemically treated wastewater; 5) Pass the biochemically treated wastewater into a sedimentation tank for secondary precipitation, and then separate slag and water to obtain harmless wastewater. 2. a kind of acidified oily wastewater harmless treatment method according to claim 1, is characterized in that: in described step 1), unslaked lime is added according to the portion ratio of 29g per liter of acidified oily wastewater; The reaction time between oily wastewater and quicklime is 5 minutes. 3. a kind of acidified oily wastewater harmless treatment method according to claim 1, is characterized in that: described step 3) specifically comprises the following steps: 31) Add iron-free aluminum sulfate according to the ratio of 2.1-3g per liter of separation liquid, and stir for 5-8min, so that the organic matter in the separation liquid can quickly agglomerate and flocculate; 32) Add polyacrylamide at a ratio of 15-19mg per liter of separation liquid after flocculation occurs, and let it stand for 30-60 minutes, so that the flocculation and flocculation can quickly flocculate and settle to the bottom of the COD reduction device to reduce COD COD wastewater. 4. a kind of acidified oily wastewater harmless treatment method according to claim 1, is characterized in that: described step 4) specifically comprises the following steps: 41) Pass the COD-reduced waste water into the ozone reaction tank, and cast ozone for oxidative decolorization, reduce the remaining COD contained in it, and decompose its macromolecular pollutants into small molecular pollutants to obtain oxidative decolorized waste water; 42) Pass the oxidatively decolorized wastewater into the A ² O reaction tank, and remove phosphate and ammonia nitrogen components in the wastewater through anaerobic, anoxic, and aerobic biochemical treatments to obtain biochemically treated wastewater. 5. A method for harmless treatment of acidified oily wastewater according to claim 1, characterized in that: in the step 5), the SO ₄ ^2- value in the harmless wastewater is 110mg/L-189mg/L , and its removal rate is 84.91%-91.02%. 6. A kind of harmless treatment method of acidified oily wastewater according to claim 1, characterized in that: in the step 5), the TP value in the harmless wastewater is 0.3mg/L-0.5mg/L, Its removal rate is 99.8%-99.81%. 7. A kind of harmless treatment method of acidified oily wastewater according to claim 1, characterized in that: in the step 5), the COD value in the harmless wastewater is 35mg/L, and its removal rate is 99.90% -99.95%.

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