Butanol and octanol wastewater treatment method

Abstract

The invention relates to the technical field of butyl octanol wastewater treatment, in particular to a butyl octanol wastewater treatment method. The method comprises the following steps: step 1, a catalytic ozonation process; step 2, anaerobic biochemical process; and step 3, performing an aerobic biochemical process. The method realizes the effects of simple process, good treatment effect, easy implementation and low treatment cost.

Description

Technical field:

[0001] The invention relates to the technical field of butanol and octanol wastewater treatment, and in particular to a butanol and octanol wastewater treatment method. Background technology:

[0002] Butyl octanol wastewater is the wastewater produced by the propylene rhodium method low-pressure carbonyl synthesis process to produce butyl octanol. The wastewater mainly contains butyraldehyde, octenal, butanol, octanol, higher carbon alcohols, sodium butyrate, etc. The pH is between 12 and 14, the COD is between 40000 mg / L and 100000 mg / L, and the total salt content is about 3%. It has the characteristics of high alkalinity, high salt, high organic matter concentration, high biological toxicity, and difficulty in biochemical treatment.

[0003] At present, the domestic disclosed methods for treating butyl octanol wastewater mainly include incineration, catalytic oxidation, stripping, multi-effect evaporation, acid extraction, etc., which have advantages but also have disadvantages. For example, a large domestic petrochemical company adopts incineration, and the wastewater is sent to an acrylonitrile incinerator for incineration treatment, and the organic matter in the wastewater is oxidized and decomposed at high temperature to convert the pollutants into harmless carbon dioxide and water. However, the high salt content in the wastewater often causes nozzle blockage, which seriously affects the long-term stable operation of the incinerator. In addition, the investment in incineration equipment is large, the energy consumption is high, and the treatment cost is high. If the treatment is not thorough, it will also cause secondary pollution, which is neither economical nor environmentally friendly. Sun Tao et al. reported the stripping-two-effect evaporation treatment process in "Qilu Petrochemical Industry". The COD removal rate of butyl octanol wastewater is 94.49%. The process flow is long and the energy consumption is high. The separated organic matter and salt need to be further treated or utilized harmlessly. Chinese patent CN101172725A discloses an acidification-Fenton oxidation process for treating octanol condensation wastewater, and the COD removal rate reaches more than 97%. Chinese patent CN103936212A discloses an extraction-Fenton oxidation process for treating butyl octanol waste alkali liquor, which first uses the heavy component of the octanol distillation tower kettle as an extractant to extract the organic matter in the waste alkali liquor, and then uses the Fenton oxidation process to treat the extracted water phase, and the COD removal rate can reach 98.3%. The wastewater extraction treatment method disclosed in the patent is only a physical transfer process of pollutants, rather than degradation and removal, and there is a large amount of extractant used, which is easy to cause secondary pollution. The Fenton oxidation process also has the disadvantages of large consumption of hydrogen peroxide and high treatment cost. Summary of the invention:

[0004] The main purpose of the invention is to solve the problem that the highly toxic, high organic matter content and high salt wastewater generated in the production of butanol is difficult to biodegrade, and to provide a butanol wastewater treatment method with high efficiency and low cost.

[0005] The technical solution adopted by the present invention is: a method for treating butyl octanol wastewater, the method comprising the following steps:

[0006] Step 1: adjusting the pH value of the butanol wastewater to 6-9 with sulfuric acid or phosphoric acid, and sending it into a loop reactor equipped with a catalyst. When the amount of the butanol wastewater initially added reaches 50%-70% of the volume of the loop reactor, start the circulation pump, continuously add the butanol wastewater and ozone gas, control the reflux rate of the circulation pump, and send the wastewater after ozone catalytic oxidation treatment into the loop reactor through the circulation pump and the heat exchanger;

[0007] Step 2: sending the butyl octanol wastewater treated in step 1 to a No. 1 sedimentation tank, settling for 20 minutes to 60 minutes, sending it to a No. 1 homogenization tank, mixing it with the wastewater discharged from the No. 2 sedimentation tank at a volume ratio of 1:1, adding urea and potassium dihydrogen phosphate, and sending it to an anaerobic biochemical tower, adding kaolin to the anaerobic biochemical tower for anaerobic biochemical treatment;

[0008] Step 3: The 1,2-butanol wastewater after anaerobic biochemical treatment is sent to the No. 2 homogenization tank, and after adding sodium carbonate or calcium carbonate, it is sent to the aerobic biochemical tower for countercurrent contact with air. The effluent is sent to the No. 2 sedimentation tank, and the separated activated sludge is sent back to the aerobic biochemical tower. Part of the wastewater is sent to the No. 1 homogenization tank, and part of the wastewater is discharged in compliance with the standards.

[0009] Furthermore, in the step 1, the catalyst in the loop reactor is a powdered CuO catalyst, and the volume ratio of the catalyst to the butyl octanol wastewater initially added to the loop reactor is 10 to 20:100.

[0010] Furthermore, in the step 1, the amount of ozone gas added is 0.1 gO3 / gCOD to 1.0 gO3 / gCOD.

[0011] Furthermore, in the step 1, the ratio of the reflux flow of the circulation pump to the flow rate of the butyl octanol wastewater added is (5-50):1.

[0012] Furthermore, in the step 1, the loop reactor comprises a venturi ejector, and a strong magnetic ring is provided on the pipeline at the inlet end of the venturi ejector.

[0013] Furthermore, in the step 1, the reaction temperature of the loop reactor is 30° C. to 60° C., and the residence time is 10 minutes to 20 minutes.

[0014] Furthermore, in the step 2, the amount of kaolin added is 1% to 3% of the mass of dry mud in the anaerobic biochemical tower.

[0015] Furthermore, in the step 2, urea and potassium dihydrogen phosphate are added to the butanol wastewater in a mass ratio of total organic carbon:total nitrogen:total phosphorus=350:5:1.

[0016] Furthermore, in the step 2, the concentration of activated sludge in the anaerobic biochemical tower is 20 g / L to 30 g / L, the circulating reflux ratio in the tower is 1:5, the temperature is 30° C. to 35° C., and the residence time is 6 h to 18 h.

[0017] Furthermore, the activated sludge used in the anaerobic biochemical tower and the aerobic biochemical tower is self-tamed microbial flora.

[0018] Furthermore, in the step three, the amount of sodium carbonate or calcium carbonate added is 2.5 to 6.0 mmol / L of butyl octanol wastewater.

[0019] Furthermore, in step three, the dissolved oxygen in the water in the aerobic biochemical tower is 3 mg / L to 6 mg / L.

[0020] Furthermore, in the step three, the residence time in the aerobic biochemical tower is 12h to 24h, the temperature in the tower is 20°C to 35°C, the activated sludge concentration is 4g / L to 6g / L, and the activated sludge return ratio is (0.5 to 2.0):1.

[0021] The beneficial effects of the present invention are:

[0022] (1) The present invention adopts the coupling of ozone catalytic oxidation process-anaerobic biochemical process-aerobic biochemical process, and combines a loop reactor, an anaerobic biochemical tower, and an aerobic biochemical tower device, which effectively solves the technical problem of difficult biochemical treatment of 1,2-butanol wastewater, and has the advantages of simple process, good treatment effect, easy implementation, and low treatment cost.

[0023] (2) The butyl octanol wastewater of the present invention passes through a venturi ejector with a strong magnetic ring in a loop reactor at a high speed, and utilizes the front and rear back pressures and the high flow rate of the wastewater at the throat to drive the magnetized wastewater to mix and cut at a high speed at the throat to form nano-scale tiny bubbles, thereby achieving efficient ozone dissolution, greatly improving the gas-solid-liquid mass transfer efficiency, improving the pollutant removal effect and treatment efficiency, and improving the biodegradability of the wastewater.

[0024] (3) The anaerobic biochemical process of the present invention introduces kaolin inert nucleating material to keep the activated sludge in a granular state for a long time, solve the sludge running phenomenon caused by the sludge not forming, and effectively maintain the sludge concentration in the anaerobic biochemical tower stable. The anaerobic biochemical process and the aerobic biochemical process give full play to the oxidation-reduction and synthesis of the microbial flora, oxidize part of the organic matter into carbon dioxide and water, and convert the other part of the organic matter back into the nutrients necessary for the organism to form new protoplasm, so that the bacteria can grow and form a stable ecosystem. Finally, the effluent COD is reduced to below 500 mg / L, achieving the degradation of organic matter in the wastewater and purifying the water quality. Description of the drawings:

[0025] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Figure 1 It is a schematic diagram of the process of the present invention.

[0027] The markings in the figure are as follows: 1. Wastewater tank; 2. Loop reactor; 3. Circulation pump; 4. Heat exchanger; 5. Sedimentation tank No. 1; 6. Homogenization tank No. 1; 7. Transfer pump No. 1; 8. Anaerobic biochemical tower; 9. Homogenization tank No. 2; 10. Transfer pump No. 2; 11. Aerobic biochemical tower; 12. Sludge return pump; 13. Sedimentation tank No. 2. Specific implementation method:

[0028] Example 1

[0029] Step 1: Take 20L of butyl octanol condensation wastewater (COD41360mg / L), and adjust the pH value to 6 with phosphoric acid. Add 600ml of butyl octanol wastewater and 60ml of powdered CuO catalyst to a 1L loop reactor, start the circulation pump, and continuously add butyl octanol wastewater (flow rate 3.6L / h) and ozone gas (0.1gO3 / gCOD) to the loop reactor, control the reflux rate of the circulation pump to 18L / h, the reaction temperature of the loop reactor to 30°C, the residence time to 10 minutes, and after continuous and stable operation, take out the water to detect COD of 6000mg / L for standby use.

[0030] Step 2: The 1,2-butanol wastewater treated in step 1 is sent to sedimentation tank No. 1, settled for 60 minutes, sent to homogenization tank No. 1 and mixed with the wastewater discharged from sedimentation tank No. 2 in step 3 (volume ratio is 1:1), urea and potassium dihydrogen phosphate are added according to total organic carbon: total nitrogen: total phosphorus = 350:5:1 (mass ratio), and then sent to an anaerobic biochemical tower, the sludge concentration is 30g / L, the kaolin addition amount is 3% of the dry mud mass, the circulation reflux ratio in the tower is 1:5, the residence time is 18h, the temperature is 35°C, and anaerobic biochemical treatment is carried out, the effluent COD is 1700mg / L, and it is stand-by.

[0031] Step 3: After anaerobic biochemical treatment, the 1,2-butanol wastewater enters the No. 2 homogenization tank, adds 6.0mmol / L of sodium carbonate, and is sent to the aerobic biochemical tower for countercurrent contact with air. The dissolved oxygen is controlled to 6mg / L, the residence time is 24h, the temperature is 30℃, the sludge concentration is 6g / L, the sludge return ratio is 2:1, and the biological filler in the tower is polypropylene hollow fiber for aerobic biochemical treatment. The effluent from the aerobic biochemical tower is sent to the No. 2 sedimentation tank to separate the activated sludge and wastewater. The activated sludge is sent back to the aerobic biochemical tower through the sludge return pump. Part of the wastewater is sent to the No. 1 homogenization tank, and part of the wastewater is discharged in compliance with the standards. The effluent COD is 285mg / L.

[0032] Example 2

[0033] Step 1: Take 20L of butyl octanol condensation wastewater (COD91280mg / L), and adjust the pH value to 9 with sulfuric acid. Add 600ml of butyl octanol wastewater and 120ml of powdered CuO catalyst to a 1L loop reactor, start the circulation pump, and continuously add butyl octanol wastewater (flow rate 1.8L / h) and ozone gas (1.0gO3 / gCOD) to the loop reactor, control the reflux rate of the circulation pump to 90L / h, the reaction temperature of the loop reactor to 60°C, the residence time to 20 minutes, and after continuous and stable operation, take out the water to detect COD of 5460mg / L for standby use.

[0034] Step 2: Send the wastewater treated in step 1 to sedimentation tank No. 1, settle for 40 minutes, send it to homogenization tank No. 1 and mix it with the wastewater discharged from sedimentation tank No. 2 (volume ratio is 1:1), add urea and potassium dihydrogen phosphate according to total organic carbon: total nitrogen: total phosphorus = 350:5:1 (mass ratio), and then send it to the anaerobic biochemical tower, the sludge concentration is 20g / L, the amount of kaolin added is 1% of the dry sludge mass, the reflux ratio is 1:5, the residence time is 12h, the temperature is 30°C, and anaerobic biochemical treatment is carried out, the effluent COD is 1580mg / L, and it is set aside.

[0035] Step 3: After anaerobic biochemical treatment, the 1,2-butanol wastewater enters the No. 2 homogenization tank, adds 3.0mmol / L of sodium carbonate, and is sent to the aerobic biochemical tower for countercurrent contact with air. The dissolved oxygen is controlled to 4mg / L, the wastewater retention time is 18h, the temperature is 30℃, the sludge concentration is 5g / L, the sludge return ratio is 1.5:1, and the biological filler in the tower is polypropylene hollow fiber for aerobic biochemical treatment. The effluent from the aerobic biochemical tower is sent to the No. 2 sedimentation tank to separate the activated sludge and wastewater. The activated sludge is sent back to the aerobic biochemical tower through the sludge return pump. Part of the wastewater is sent to the No. 1 homogenization tank, and part of the wastewater is discharged in compliance with the standards. The effluent COD is 365mg / L.

[0036] Example 3

[0037] Step 1: Take 20L of butyl octanol condensation wastewater (COD61240mg / L), and adjust the pH value to 7 with sulfuric acid. Add 600ml of butyl octanol wastewater and 90ml of powdered CuO catalyst to a 1L loop reactor, start the circulation pump, and continuously add butyl octanol wastewater (flow rate 2.4L / h) and ozone gas (0.8gO3 / gCOD) to the loop reactor, control the reflux rate of the circulation pump to 120L / h, the reaction temperature of the loop reactor to 50°C, the residence time to 15 minutes, and after continuous and stable operation, take out the water to detect COD of 5870mg / L for standby use.

[0038] Step 2: Send the wastewater treated in step 1 to sedimentation tank No. 1, settle for 20 minutes, send it to homogenization tank No. 1 and mix it with the wastewater discharged from sedimentation tank No. 2 (volume ratio is 1:1), add urea and potassium dihydrogen phosphate according to total organic carbon: total nitrogen: total phosphorus = 350:5:1 (mass ratio), and then send it to the anaerobic biochemical tower, control the sludge concentration to 25g / L, add kaolin to 2% of the dry sludge mass, the reflux ratio is 1:5, the residence time is 6h, the temperature is 35°C, and perform anaerobic biochemical treatment. The effluent COD is 2348mg / L for standby use.

[0039] Step 3: After anaerobic biochemical treatment, the 1,2-butanol wastewater enters the No. 2 homogenization tank, adds 5.0mmol / L of calcium carbonate, and is sent to the aerobic biochemical tower for countercurrent contact with air. The dissolved oxygen is controlled to 3mg / L, the wastewater retention time is 12h, the temperature is 35℃, the sludge concentration is 4g / L, the sludge return ratio is 0.5:1, and the biological filler in the tower is polypropylene hollow fiber for aerobic biochemical treatment. The effluent from the aerobic biochemical tower is sent to the No. 2 sedimentation tank to separate the activated sludge and wastewater. The activated sludge is sent back to the aerobic biochemical tower through the sludge return pump. Part of the wastewater is sent to the No. 1 homogenization tank, and part of the wastewater is discharged in compliance with the standards. The effluent COD is 495mg / L.

[0040] In summary, as shown in Examples 1-3, the final effluent COD dropped below 500 mg / L, achieving the degradation of organic matter in the butyl octanol wastewater and purifying the water quality.

[0041] It can be understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A method for treating butyl octanol wastewater, characterized in that: The steps of this method are as follows: Step 1: adjusting the pH value of the butanol wastewater to 6-9 with sulfuric acid or phosphoric acid, and sending it into a loop reactor equipped with a catalyst. When the amount of the butanol wastewater initially added reaches 50%-70% of the volume of the loop reactor, start the circulation pump, continuously add the butanol wastewater and ozone gas, control the reflux rate of the circulation pump, and send the wastewater after ozone catalytic oxidation treatment into the loop reactor through the circulation pump and the heat exchanger; Step 2: sending the butyl octanol wastewater treated in step 1 to a No. 1 sedimentation tank, settling for 20 minutes to 60 minutes, sending it to a No. 1 homogenization tank, mixing it with the wastewater discharged from the No. 2 sedimentation tank at a volume ratio of 1:1, adding urea and potassium dihydrogen phosphate, and sending it to an anaerobic biochemical tower, adding kaolin to the anaerobic biochemical tower for anaerobic biochemical treatment; Step 3: The 1,2-butanol wastewater after anaerobic biochemical treatment is sent to the No. 2 homogenization tank, and after adding sodium carbonate or calcium carbonate, it is sent to the aerobic biochemical tower for countercurrent contact with air. The effluent is sent to the No. 2 sedimentation tank, and the separated activated sludge is sent back to the aerobic biochemical tower. Part of the wastewater is sent to the No. 1 homogenization tank, and part of the wastewater is discharged in compliance with the standards.

2. The method for treating butyl octanol wastewater according to claim 1, wherein: In the step 1, the catalyst in the loop reactor is a powdered CuO catalyst, and the volume ratio of the catalyst to the butyl octanol wastewater initially added to the loop reactor is 10 to 20:

100.

3. The method for treating butyl octanol wastewater according to claim 1, wherein: In the step 1, the amount of ozone gas added is 0.1 gO3 / gCOD to 1.0 gO3 / gCOD.

4. The method for treating butyl octanol wastewater according to claim 1, wherein: In the step 1, the ratio of the reflux flow of the circulation pump to the flow rate of the butyl octanol wastewater added is (5-50):

1.

5. The method for treating butyl octanol wastewater according to claim 1, wherein: The loop reactor in step 1 includes a venturi ejector, and a strong magnetic ring is provided on the pipeline at the inlet end of the venturi ejector.

6. The method for treating butyl octanol wastewater according to claim 1, wherein: In the step 1, the reaction temperature of the loop reactor is 30° C. to 60° C., and the residence time is 10 minutes to 20 minutes.

7. The method for treating butyl octanol wastewater according to claim 1, wherein: The amount of kaolin added in the step 2 is 1% to 3% of the mass of the dry mud in the anaerobic biochemical tower.

8. The method for treating butyl octanol wastewater according to claim 1, wherein: In the step 2, urea and potassium dihydrogen phosphate are added to the butyl octanol wastewater in a mass ratio of total organic carbon:total nitrogen:total phosphorus=350:5:

1.

9. The method for treating butyl octanol wastewater according to claim 1, wherein: In the step 2, the concentration of activated sludge in the anaerobic biochemical tower is 20 g / L to 30 g / L, the circulating reflux ratio in the tower is 1:5, the temperature is 30° C. to 35° C., and the residence time is 6 h to 18 h.

10. The method for treating butyl octanol wastewater according to claim 1, characterized in that: The activated sludge used in the anaerobic biochemical tower and the aerobic biochemical tower is self-tamed microbial flora.

11. The method for treating butyl octanol wastewater according to claim 1, characterized in that: In the step 3, the amount of sodium carbonate or calcium carbonate added is 2.5-6.0 mmol / L of butyl octanol wastewater.

12. The method for treating butyl octanol wastewater according to claim 1, characterized in that: In the step 3, the dissolved oxygen in the water of the aerobic biochemical tower is 3 mg / L to 6 mg / L.

13. The method for treating butyl octanol wastewater according to claim 1, characterized in that: In the step 3, the residence time in the aerobic biochemical tower is 12h to 24h, the temperature in the tower is 20°C to 35°C, the activated sludge concentration is 4g / L to 6g / L, and the activated sludge return ratio is (0.5 to 2.0):1.

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