A method for harmless treatment of acidified oil wastewater

Abstract

The present invention relates to a method for harmless treatment of acidified oil wastewater, comprising the following steps: 1) feeding the acidified oil wastewater into a high-concentration sulfate removal device, and adding quicklime for reaction to remove the high-concentration sulfate in the wastewater and adjust the pH value of the wastewater; 2) separating the wastewater residue and water of the sulfate-removed wastewater to obtain a separation liquid, and feeding it into a COD reduction device through a distribution well; 3) sequentially adding ferric-free aluminum sulfate and polyacrylamide to the separation liquid for reaction to cause the separation liquid to agglomerate, flocculate and precipitate; 4) feeding the wastewater with reduced COD into a biochemical treatment system, and sequentially using an ozone reaction tank and an A 2 / O reaction tank for advanced treatment; 5) feeding the wastewater after biochemical treatment into a sedimentation tank for secondary sedimentation to obtain harmless wastewater. Through this method, high-concentration sulfate, COD and phosphate in acidified oil wastewater can be harmlessly treated with high efficiency and low cost, and the acidified oil wastewater can meet the national discharge standards.

Description

Technical Field

[0001] The present invention belongs to the technical field of acidified oil wastewater treatment, and particularly relates to a method for harmless treatment of acidified oil wastewater. Background Art

[0002] In recent years, the application of reprocessing waste materials for producing oils and fats into chemical raw materials has been increasing day by day. Vegetable acidified oil can be used as an important raw material for producing daily chemicals. During its production process, a large amount of wastewater containing high concentrations of organic matter and high concentrations of sulfates will inevitably be generated at the same time. Among them, most of the organic substances are synthetic and are difficult to degrade naturally in nature. Among the pollutants discharged into the wastewater, many substances themselves or the small molecular substances generated by degradation have great carcinogenic or mutagenic effects. If these wastewaters are directly discharged into nature, it will cause great toxic pollution to the environment.

[0003] Due to the characteristics of high concentration of sulfates, high concentration of COD, strong acidity, high concentration of phosphates, and poor biodegradability in acidified oil wastewater, ordinary sewage treatment processes cannot treat it to meet the national discharge standards. At the same time, the existing acidified oil treatment processes have not really achieved low power consumption, low cost, and efficient and rapid removal of high concentrations of sulfates, COD, and phosphates in the wastewater.

[0004] Therefore, aiming at the specific wastewater treatment problems of current acidified oil production enterprises, it is urgent to develop a high-efficiency and low-cost method for harmless treatment of acidified oil to solve the above existing problems. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides a method for harmless treatment of acidified oil wastewater, which can harmlessly treat high concentrations of sulfates, COD, and phosphates in acidified oil wastewater with high efficiency and low cost, and the acidified oil wastewater treated by this method can meet the national discharge standards.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows:

[0007] A method for harmless treatment of acidified oil wastewater, after pre-treating the acidified oil wastewater, then performing deep treatment. The specific treatment method includes the following steps:

[0008] 1) Pass the acidified oil wastewater into a high-concentration sulfate removal device, and add quicklime to the device for reaction to remove the high-concentration sulfates in the wastewater and adjust the pH value of the wastewater to 6-9 to obtain wastewater with sulfates removed;

[0009] 2) Separate the slag and water from the wastewater with sulfates removed to obtain a separation liquid, and pass the separation liquid into a COD reduction device through a distribution well;

[0010] 3) adding iron-free aluminum sulfate and polyacrylamide into the COD reduction device in sequence to react with the separated liquid, causing the separated liquid to agglomerate, flocculate, and precipitate, thereby obtaining wastewater with reduced COD;

[0011] 4) The wastewater with reduced COD is passed into the biochemical treatment system, and the ozone reaction tank, A 2 The O reaction tank deeply treats the wastewater with reduced COD to obtain biochemically treated wastewater;

[0012] 5) The wastewater after biochemical treatment is passed into a sedimentation tank for secondary sedimentation, and then the slag and water are separated to obtain harmless wastewater.

[0013] Preferably, in the step 1), quicklime is added at a ratio of 29 g per liter of acidified oil wastewater; and the reaction time of the acidified oil wastewater and quicklime is 5 minutes.

[0014] Preferably, the step 3) specifically includes the following steps:

[0015] 31) Add 2.1-3 g of iron-free aluminum sulfate per liter of separated liquid and stir for 5-8 minutes to allow the organic matter in the separated liquid to rapidly clump and flocculate;

[0016] 32) After the agglomerates are formed, polyacrylamide is added at a ratio of 15-19 mg per liter of separation liquid and allowed to stand for 30-60 minutes to allow the agglomerates to rapidly flocculate and settle to the bottom of the COD reduction device, thereby obtaining COD-reduced wastewater.

[0017] Preferably, the step 4) specifically includes the following steps:

[0018] 41) The wastewater with reduced COD is passed into an ozone reaction tank and ozone is added for oxidative decolorization, thereby reducing the remaining COD contained therein and decomposing the high molecular pollutants into small molecular pollutants, thereby obtaining oxidatively decolorized wastewater;

[0019] 42) The oxidative decolorization wastewater is passed into A 2 O reaction tank, and through anaerobic, anoxic and aerobic biochemical treatment, remove phosphate and ammonia nitrogen components in the wastewater to obtain biochemically treated wastewater.

[0020] Preferably, in step 5), SO4 in the wastewater is detoxified 2- The value is 110mg / L-189mg / L, and the removal rate is 84.91%-91.02%.

[0021] Preferably, in step 5), the TP value in the harmless wastewater is 0.3 mg / L-0.5 mg / L, and the removal rate is 99.8%-99.81%.

[0022] Preferably, in step 5), the COD value of the harmless wastewater is 35 mg / L, and its removal rate is 99.90%-99.95%.

[0023] Technical effects and advantages of the present invention:

[0024] 1. A method for harmless treatment of acidified oil wastewater provided by the present invention. The acidified oil wastewater reacts by adding quicklime to remove high-concentration sulfate and adjust the pH value, and then the slag and water are separated to obtain a separation liquid. Then, ferric-free aluminum sulfate, polyacrylamide are added in sequence to react with the separation liquid, so that the separation liquid forms flocs, flocculates and precipitates to obtain wastewater with reduced COD. Finally, the wastewater with reduced COD is introduced into a biochemical treatment system for deep treatment to obtain the wastewater after biochemical treatment, and the wastewater after biochemical treatment is subjected to secondary sedimentation and slag-water separation to obtain harmless wastewater, which can efficiently and low-costly harmlessly treat high-concentration sulfate, COD and phosphate in acidified oil wastewater, and can make the acidified oil wastewater meet the national discharge standards. Therefore, this acidified oil wastewater treatment method has great promotion and application value.

[0025] 2. A method for harmless treatment of acidified oil wastewater provided by the present invention. By adding quicklime with low cost and no other by-products, as well as ferric-free aluminum sulfate and polyacrylamide with low cost and high efficiency in the pretreatment stage, high-concentration sulfate and part of COD in the wastewater can be removed, and at the same time, it can also play a role in adjusting the pH value of the wastewater. Its process for treating acidified oil wastewater has low cost, good effect, high efficiency, and can effectively reduce the pressure in the subsequent biochemical treatment stage. Description of the drawings

[0026] Figure 1 is the treatment effect diagram of removing SO4 in the acidified oil wastewater of the present invention 2- ;

[0027] Figure 2 is the treatment effect diagram of removing COD in the acidified oil wastewater of the present invention;

[0028] Figure 3 is the treatment effect diagram of removing TP in the acidified oil wastewater of the present invention;

[0029] Figure 4 is the structural schematic diagram of the high-concentration sulfate removal device used in the present invention;

[0030] Figure 5 is the structural schematic diagram of the COD reduction device used in the present invention.

[0031] Reference numerals in the figures: 1. High-concentration sulfate removal device; 101. Sulfate removal device housing; 102. First overflow buffer plate; 103. Preliminary neutralization reaction chamber; 104. Deep neutralization reaction chamber; 105. Acidified oil wastewater inlet pipe; 106. First discharge port; 107. Second discharge port; 108. Neutralizing agent feed port; 109. Drainage valve; 110. Semi-circular 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. Agglomerating agent inlet pipe; 207. Flocculant inlet pipe; 208. Floc discharge port; 209. Separation liquid inlet pipe; 210. Drainage port; 211. Floc discharge pipe; 212. Housing cover plate; 213. Inlet control valve. Detailed implementation manners

[0032] The following embodiments given in conjunction with the accompanying drawings further illustrate the present invention in detail.

[0033] A method for harmless treatment of acidified oil wastewater, which pre-treats the acidified oil wastewater and then performs deep treatment. The specific treatment method includes the following steps:

[0034] 1) Feed the acidified oil wastewater into the high-concentration sulfate removal device, and add quicklime to the device for reaction to remove the high-concentration sulfate in the wastewater and adjust the pH value of the wastewater to 6-9 to obtain the wastewater with sulfate removed. Further, in order to ensure the pH value required for subsequent treatment of the acidified oil wastewater, an appropriate amount of quicklime can be added again and reacted for 5 minutes.

[0035] Specifically in implementation, the quicklime is added in a dosage ratio of 29 g per liter of acidified oil wastewater.

[0036] Specifically in implementation, the reaction time of the acidified oil wastewater and quicklime is 5 minutes.

[0037] 2) Separate the slag and water from the wastewater with sulfate removed to obtain the separation liquid, and feed the separation liquid into the COD reduction device through the distribution well.

[0038] 3) Add ferric-free aluminum sulfate and polyacrylamide to the COD reduction device in sequence for reaction with the separation liquid to make the separation liquid agglomerate, flocculate and precipitate to obtain the wastewater with COD reduced. Specifically, it includes the following steps:

[0039] 31) Add ferric-free aluminum sulfate in a dosage ratio of 2.1-3 g per liter of separation liquid and stir for 5-8 minutes to make the organic substances in the separation liquid quickly agglomerate and flocculate;

[0040] 32) After the formation of flocculation clusters, polyacrylamide is added in a dosage ratio of 15 - 19 mg per liter of separation liquid, and it is left standing for 30 - 60 minutes to rapidly flocculate and precipitate the flocculation clusters to the bottom of the COD reduction device, obtaining wastewater with reduced COD.

[0041] 4) The wastewater with reduced COD is introduced into the biochemical treatment system, and the ozone reaction tank and A 2 O reaction tank are successively used to deeply treat the wastewater with reduced COD, obtaining the wastewater after biochemical treatment. Specifically, it includes the following steps:

[0042] 41) The wastewater with reduced COD is introduced into the ozone reaction tank, and ozone is added for oxidation decolorization, reducing the remaining COD contained therein, and decomposing its high molecular pollutants into small molecular pollutants, obtaining the oxidized and decolorized wastewater;

[0043] 42) The oxidized and decolorized wastewater is introduced into the A 2 O reaction tank, and through anaerobic, anoxic, and aerobic biochemical treatments, the phosphate and ammonia nitrogen components in the wastewater are removed, obtaining the wastewater after biochemical treatment.

[0044] 5) The wastewater after biochemical treatment is introduced into the sedimentation tank for secondary sedimentation, and then the slag and water are separated to obtain harmless wastewater.

[0045] Specifically in implementation, the SO4 2- value in the harmless wastewater is 110 mg / L - 189 mg / L, and its removal rate is 84.91% - 91.02%.

[0046] Specifically in implementation, the TP value in the harmless wastewater is 0.3 mg / L - 0.5 mg / L, and its removal rate is 99.8% - 99.81%.

[0047] Specifically in implementation, the COD value in the harmless wastewater is 35 mg / L, and its removal rate is 99.90% - 99.95%.

[0048] In this implementation, steps 1), 2), and 3) are the pretreatment stage of acidified oil wastewater. In this stage, quicklime with low cost and no other by - products is used as the first step of the pretreatment stage. At the same time, a certain proportion of iron - free aluminum sulfate and polyacrylamide with low cost and high efficiency are added, and it is carried out in the COD reduction device. The purpose is to remove the high - concentration sulfate and part of the COD in the acidified oil wastewater, and at the same time, it can also play a role in adjusting the pH of the acidified oil wastewater, reducing the pressure for the subsequent biochemical treatment stage. In this stage, the SS removal rate of the acidified oil wastewater is as high as 90%, the sulfate removal rate is 90%, the pH value can be adjusted from the original 2 of the acidified oil wastewater to 6 - 9, and the biodegradability B / C ≥ 0.5. It can fully meet the required conditions for the subsequent biochemical treatment.

[0049] In this embodiment, step 4) is the advanced treatment stage of acidified oil wastewater. In this stage, ozone is introduced into the ozone reaction tank in the biochemical reaction system to remove the remaining COD in the wastewater, and the turbidity and macromolecular compounds of the wastewater are degraded into small molecular compounds, and then enter the A 2 / O reaction tank in the biochemical treatment system, the first anaerobic tank. The main function of this tank is to release phosphorus, increasing the concentration of P in the sewage, and the dissolved organic matter is absorbed by microbial cells, resulting in a decrease in the BOD concentration in the wastewater; in addition, part of the ammonia nitrogen is removed due to cell synthesis, reducing the ammonia nitrogen concentration in the wastewater. In the anoxic tank, denitrifying bacteria use the organic matter in the wastewater as a carbon source to reduce the large amount of NO3-N and NO2-N brought into the reflux mixture to N and release it into the air. Therefore, the BOD concentration decreases, the NO3-N concentration decreases significantly, and the change in phosphorus is small. In the aerobic tank, the organic matter is biochemically degraded by microorganisms and continues to decrease; the organic nitrogen is ammoniated and then nitrified, resulting in a significant decrease in the NH3-N concentration, but with the nitrification process, the concentration of NO3-N increases, and P also decreases at a relatively fast rate with the excessive uptake of polyphosphate bacteria. Among them, the removal rates of pollutants such as COD and TP in the wastewater are about 60% or so, and the removal rate of the NH3-N concentration is about 99%, thus removing the nitrogen and phosphorus in the wastewater.

[0050] In this embodiment, the acidified oil wastewater introduced into the high-concentration sulfate removal device reacts by adding quicklime to remove high-concentration sulfate and adjust the pH value, and then slag-water separation is carried out to obtain a separation liquid; then the separation liquid is introduced into the COD reduction device, and then ferric-free aluminum sulfate, polyacrylamide are added in turn to react with the separation liquid to make the separation liquid flocculate and precipitate in clumps, obtaining the wastewater with reduced COD; finally, the wastewater with reduced COD is introduced into the biochemical treatment system for advanced treatment to obtain the wastewater after biochemical treatment, and the wastewater after biochemical treatment is subjected to secondary sedimentation and slag-water separation to obtain harmless wastewater, which can efficiently and cost-effectively harmlessly treat high-concentration sulfate, COD and phosphate in acidified oil wastewater, and can make the acidified oil wastewater meet the national discharge standards. Therefore, this acidified oil wastewater treatment method has great promotion and application value.

[0051] Example 1

[0052] The acidified oil wastewater of an acidified oil wastewater treatment plant has a pH value of 1.9, a COD concentration value of 74230 mg / L, SO4 2- value of 839 mg / L, and a TP value of 302 mg / L.

[0053] The acidified oil wastewater is fed into a high-concentration sulfate removal device, and quicklime is added at a ratio of 29 g per liter of acidified oil wastewater. After a reaction time of 5 minutes, the pH value of the wastewater is 6. To ensure the pH required for subsequent treatment, an appropriate amount of quicklime is added again, and the reaction is carried out for another 5 minutes. At this time, the pH value of the wastewater is 8. Then, the slag and water are separated to obtain a separation liquid, and the separation liquid is fed into a COD reduction device through a distribution well. Ferric-free aluminum sulfate is added to the separation liquid at a dosage ratio of 3 g per liter of separation liquid, and it is stirred for 5 minutes to quickly agglomerate and flocculate the organic substances in the separation liquid. Then, polyacrylamide is added to the separation liquid at a dosage ratio of 19 mg per liter, and it is allowed to stand for 30 minutes to quickly flocculate and precipitate the agglomerated and flocculated organic substances to the bottom of the COD reduction device, obtaining wastewater with reduced COD. The wastewater with reduced COD is fed into an ozone reaction tank, and strongly oxidizing ozone is added for oxidation and decolorization, reducing the remaining COD contained therein and decomposing its high-molecular pollutants into small-molecular pollutants, obtaining decolorized wastewater through oxidation. The decolorized wastewater is fed into an A 2 O reaction tank, and through anaerobic, anoxic, and aerobic biochemical treatments, the phosphate and ammonia nitrogen components in the wastewater are removed, obtaining wastewater after biochemical treatment. The wastewater after biochemical treatment is fed into a sedimentation tank for secondary sedimentation, and then the slag and water are separated to obtain harmless wastewater.

[0054] In this embodiment, the SO4 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%.

[0055] Example 2

[0056] The acidified oil wastewater from an acidified oil wastewater treatment plant has a pH value of 3.4, a COD concentration value of 34,230 mg / L, a SO4 2- value of 729 mg / L, and a TP value of 265 mg / L.

[0057] The acidified oil wastewater is fed into a high-concentration sulfate removal device, and quicklime is added at a ratio of 29 g per liter of the acidified oil wastewater. After a reaction time of 5 min, the pH value of the wastewater is 8. To ensure the pH required for subsequent treatment, an appropriate amount of quicklime is added and the reaction is carried out for another 5 min. At this time, the pH value of the wastewater is 9. Then, slag-water separation is performed to obtain a separation liquid, which is then fed into a COD reduction device through a distribution well. Ferric-free aluminum sulfate is added to the separation liquid at a dosage ratio of 2.1 g per liter of the separation liquid, and it is stirred for 8 min to rapidly agglomerate and flocculate the organic substances in the separation liquid. Then, polyacrylamide is added at a dosage ratio of 15 mg per liter of the separation liquid, and it is allowed to stand for 60 min to rapidly flocculate and precipitate the agglomerated and flocculated organic substances to the bottom of the COD reduction device, obtaining wastewater with reduced COD. The wastewater with reduced COD is fed into an ozone reaction tank, and strongly oxidizing ozone is added for oxidative decolorization, reducing the remaining COD contained therein and decomposing its high-molecular pollutants into low-molecular pollutants, obtaining oxidatively decolorized wastewater. The oxidatively decolorized wastewater is fed into an A 2 O reaction tank, and through anaerobic, anoxic, and aerobic biochemical treatments, the phosphate and ammonia nitrogen components in the wastewater are removed, obtaining biochemically treated wastewater. The biochemically treated wastewater is fed into a sedimentation tank for secondary sedimentation, and then slag-water separation is performed to obtain harmless wastewater.

[0058] In this embodiment, the SO4 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%.

[0059] Example 3

[0060] See Figure 4As shown in the figure, the high-concentration sulfate removal device 1 includes a sulfate removal device housing 101. The inner cavity of the sulfate removal device housing 101 is divided into a preliminary neutralization reaction chamber 103 and a deep neutralization reaction chamber 104 by a first overflow buffer plate 102. 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. The two sides are respectively provided with a neutralizing agent inlet 108 and a drainage valve 109. The acidified oil wastewater inlet pipe 105, the first discharge port 106 and the neutralizing agent inlet 108 are all connected to the preliminary neutralization reaction chamber 103; the second discharge port 107 and the drainage valve 109 are both connected to the deep neutralization reaction chamber 104. The bottom of the inner cavity of the preliminary neutralization reaction chamber 103 is provided with a semi-circular plate 110. The circumcircle of the semi-circular plate 110 is respectively connected to the inner side wall and the bottom surface of the preliminary neutralization reaction chamber 103; the first discharge port 106 is arranged at the connection between the semi-circular plate 110 and the bottom surface of the preliminary neutralization reaction chamber 103. The bottom of the inner cavity of the deep neutralization reaction chamber 104 is provided with a conical plate 111. The outer circle of the conical plate 111 is connected to the inner side wall of the deep neutralization reaction chamber 104, and the cone point is connected to the bottom surface of the deep neutralization reaction chamber 104; the second discharge port 107 is arranged at the connection between the cone point of the conical plate 111 and the bottom surface of the deep neutralization reaction chamber 104. The upper end of the first overflow buffer plate 102 is provided with an outward turned edge, and the outward turning angle of the outward turned edge is 45°. A plurality of drainage valves 109 are provided, and the plurality of drainage valves 109 are arranged at intervals from top to bottom on the outside of the deep neutralization reaction chamber 104.

[0061] When treating high-concentration sulfate in acidified oil wastewater in this embodiment, the acidified oil wastewater flows into the preliminary neutralization reaction chamber 103 from the acidified oil wastewater inlet pipe 105. The acidified oil wastewater undergoes a neutralization reaction with quicklime entering from the neutralizing agent inlet 108 under the action of gravity. After the preliminary neutralization reaction chamber 103 is full, the inlet flow rate and velocity of the acidified oil wastewater are reduced, so that the wastewater mixture flows into the deep neutralization reaction chamber 104 through the first overflow buffer plate 102. The wastewater mixture undergoes a deep neutralization reaction under the action of gravity, and secondary precipitation separation is carried out, which can effectively ensure the removal effect of high-concentration sulfate. At the same time, the utilization rate of the neutralizing agent can be improved by carrying out a deep neutralization reaction, and the cost can be reduced. After the neutralization reaction is completed, the first discharge port 106 is opened to discharge the precipitate in the preliminary neutralization reaction chamber 103. The separated liquid obtained by precipitation separation in the deep neutralization reaction chamber 104 is introduced into the COD reduction device through the drainage valve 109, and the separated precipitate is discharged through the second discharge port 107.

[0062] Example 4

[0063] See Figure 5As shown, 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 cavity of the housing 1 into a flocculation chamber 3 and a secondary sedimentation chamber 4, and the secondary sedimentation chamber 4 is located outside the flocculation chamber 3. A stirring device 5 is provided in the flocculation chamber 3. The stirring device 5 includes a stirring rod 51 and a stirring blade 52 fixedly connected to one end of the stirring rod 51. The end of the stirring rod 51 connected with the stirring blade 52 is located in the flocculation chamber 3, and the other end extends out through the stirring port and is exposed at the top of the housing cover 12. A flocculant inlet pipe 6 and a flocculant inlet pipe 7 are provided at the top of the flocculation chamber 3, and a floc discharge port 8 and a separation liquid inlet pipe 9 are provided at the bottom. A drain port 10 is provided on one side of the upper end of the secondary sedimentation chamber 4, and floc discharge pipes 11 are provided on the opposite sides of the lower end. A housing cover 12 is provided at the top of the COD reduction device housing 1. The housing cover 12 is respectively provided with a flocculant inlet pipe installation hole, a flocculant inlet pipe installation hole and a stirring port. The stirring port is opened at the center of the housing cover 12. The flocculant inlet pipe installation hole and the flocculant inlet pipe installation hole are respectively located beside the stirring port. One ends of the flocculant inlet pipe 6 and the flocculant inlet pipe 7 respectively extend into the flocculation chamber 3 through the flocculant inlet pipe installation hole and the flocculant inlet pipe installation hole, and the other ends are respectively exposed above the housing cover 12. One ends of the flocculant inlet pipe 6 and the flocculant inlet pipe 7 exposed above the housing cover 12 are respectively provided with a chemical agent control valve, a chemical agent flow rate meter and a chemical agent flow meter for convenient and accurate dosing of the flocculant and the flocculant. The bottom cross section of the COD reduction device housing 1 is arc-shaped, and the floc discharge port 8 is opened at the center of the bottom of the COD reduction device housing 1; a water inlet is opened on one side of the floc discharge port 8, and one end of the separation liquid inlet pipe 9 extends into the flocculation chamber 3 through the water inlet, and the other end is exposed outside the COD reduction device housing 1, and a water inlet control valve, a water inlet flow rate meter and a water inlet flow meter are sequentially arranged thereon for controlling the water inlet speed of the wastewater.

[0064] When treating COD in acidified oil wastewater in this embodiment, the separation liquid flows into the flocculation agglomeration chamber 3 at a constant speed and in a fixed quantity through the separation liquid inlet pipe 9; after a certain amount of separation liquid flows into the flocculation agglomeration chamber 3, the flocculation agent and the coagulant are added at a constant speed and in a fixed quantity according to the inflow of the separation liquid through the flocculation agent inlet pipe 6 and the coagulant inlet pipe 7, and the speed is controlled by the stirring rod 6 for stirring, so that the separation liquid in the flocculation agglomeration chamber 3 quickly forms flocs and flocculates; after the separation liquid in the flocculation agglomeration chamber 3 is full, the inlet control valve is used to control the reduction of the inlet flow rate and velocity of the separation liquid, and at the same time, the dosing control valve is used to adjust the dosing timing of the flocculation agent and the coagulant, so that the separation liquid flows into the secondary sedimentation chamber 4 through the outer turned edge of the second overflow buffer plate 2, and secondary flocculation and agglomeration are carried out by gravity to improve the reduction rate of COD, thereby effectively improving the reduction effect of COD. After the secondary flocculation and agglomeration are completed, the wastewater with reduced COD enters the biochemical treatment system through the drain port 10, and the flocs are discharged from the floc discharge pipe 11. The flocs in the flocculation agglomeration chamber 3 are discharged through the floc discharge port 8.

[0065] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the inventive concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention.

Claims

1. A method for harmless treatment of acidified oil wastewater, characterized in that: the acidified oil wastewater is pretreated and then subjected to deep treatment, and the specific treatment method includes the following steps: 1) The acidified oil wastewater is passed through a high-concentration sulfate removal device, and quicklime is added to the device for reaction to remove high-concentration sulfate in the wastewater, and the pH value of the wastewater is adjusted to 6-9 to obtain sulfate-removed wastewater; The high-concentration sulfate removal device comprises a sulfate removal device shell, wherein the inner cavity of the sulfate removal device shell is divided into a preliminary neutralization reaction chamber and a deep neutralization reaction chamber by a first overflow buffer plate; an acidified oil wastewater inlet pipe is provided on the top of the sulfate removal device shell, a first discharge port and a second discharge port are provided on the bottom, and a neutralizer feed port and a drain valve are provided on both sides; the acidified oil wastewater inlet pipe, the first discharge port and the neutralizer feed port are all connected to the preliminary neutralization reaction chamber; the second discharge port and the drain valve are both connected to the deep neutralization reaction chamber; a semicircular plate is provided at the bottom of the inner cavity of the preliminary neutralization reaction chamber, and the semicircular plate is provided with a The circumscribed circle is respectively connected to the inner side wall and the bottom surface of the preliminary neutralization reaction chamber; the first discharge port is arranged at the junction of the semicircular plate and the bottom surface of the preliminary neutralization reaction chamber; a conical plate is provided at the bottom of the inner cavity of the deep neutralization reaction chamber, the outer circle of the conical plate is connected to the inner side wall of the deep neutralization reaction chamber, and the cone point is connected to the bottom surface of the deep neutralization reaction chamber; the second discharge port is arranged at the junction of the cone point of the conical plate and the bottom surface of the deep neutralization reaction chamber; the upper end of the first overflow buffer plate is set as an outward turning edge, and the outward turning angle of the outward turning edge is 45°; a plurality of drain valves are provided, and the plurality of drain valves are sequentially arranged at intervals from top to bottom on the outside of the deep neutralization reaction chamber; 2) Separate the wastewater from which sulfate has been removed to obtain a separated liquid, which is then introduced into the COD reduction device through a water distribution well; 3) Iron-free aluminum sulfate and polyacrylamide are sequentially added to the COD reduction device to react with the separated liquid, causing the separated liquid to agglomerate, flocculate, and precipitate, thereby obtaining wastewater with reduced COD; 4) The wastewater with reduced COD is passed into the biochemical treatment system, and the ozone reaction tank, A 2 The O reaction tank deeply treats the wastewater with reduced COD to obtain biochemically treated wastewater; 5) The wastewater after biochemical treatment is passed into the sedimentation tank for secondary sedimentation, and then the slag and water are separated to obtain harmless wastewater.

2. The method for harmless treatment of acidified oil wastewater according to claim 1, characterized in that: In the step 1), quicklime is added at a ratio of 29 g per liter of acidified oil wastewater; and the reaction time of the acidified oil wastewater and quicklime is 5 minutes.

3. The method for harmless treatment of acidified oil wastewater according to claim 1, characterized in that: The step 3) specifically includes the following steps: 31) Add 2.1-3g of iron-free aluminum sulfate per liter of separated liquid and stir for 5-8 minutes to allow the organic matter in the separated liquid to quickly flocculate; 32) After the clumping and flocculation are produced, polyacrylamide is added at a ratio of 15-19 mg per liter of separation liquid and allowed to stand for 30-60 minutes to allow the clumping and flocculation to quickly flocculate and settle to the bottom of the COD reduction device to obtain COD-reduced wastewater.

4. The method for harmless treatment of acidified oil wastewater according to claim 1, characterized in that: The step 4) specifically includes the following steps: 41) The wastewater with reduced COD is passed into an ozone reaction tank and oxidized and decolorized by ozone, thereby reducing the remaining COD contained therein and decomposing the high molecular pollutants into small molecular pollutants, thereby obtaining oxidatively decolorized wastewater; 42) The oxidative decolorization wastewater is passed into A 2 O reaction tank, and through anaerobic, anoxic and aerobic biochemical treatment, remove phosphate and ammonia nitrogen components in the wastewater to obtain biochemically treated wastewater.

5. The method for harmless treatment of acidified oil wastewater according to claim 1, characterized in that: In the step 5), SO4 in the wastewater is detoxified 2- The value is 110mg / L-189mg / L, and the removal rate is 84.91%-91.02%.

6. The method for harmless treatment of acidified oil wastewater according to claim 1, characterized in that: In the step 5), the TP value in the harmless wastewater is 0.3 mg / L-0.5 mg / L, and the removal rate is 99.8%-99.81%.

7. The method for harmless treatment of acidified oil wastewater according to claim 1, characterized in that: In step 5), the COD value in the harmless wastewater is 35 mg / L, and the removal rate is 99.90%-99.95%.

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