CN206328290U - The aerobic collaboration processing cutting liquid waste plant of coagulation anaerobic hydrolysis - Google Patents

Abstract

The utility model discloses a kind of aerobic collaboration processing cutting liquid waste plant of coagulation anaerobic hydrolysis, the device includes coagulating basin, the first sedimentation basin, anaerobic fixed film reactor, the second sedimentation basin, aerobic reaction tank and the 3rd sedimentation basin.Aluminium polychloride and polyacrylamide are added in coagulating basin.Alkali is added in anaerobic fixed film reactor, pH of mixed in anaerobic fixed film reactor is maintained in optimum range.Glucose Synergistic degradation part hardly degraded organic substance is added in aerobic reaction tank.Of the present utility model method is simple, and operational management is convenient, and the COD in Cutting Liquid Wastewater and the clearance of petroleum-type can be made to reach more than 99%, system water outlet COD, BOD₅, petroleum-type, suspension and pH reach《Sewage is discharged into town sewer water standard (GB/T31962 2015)》The requirement of middle C grades of discharge standard.

Description

Coagulation-anaerobic hydrolysis-aerobic cooperative treatment of cutting fluid wastewater device

technical field

The utility model belongs to the technical field of sewage treatment in environmental engineering, and relates to a device for coagulation-anaerobic hydrolysis-aerobic cooperative treatment of cutting fluid waste water.

Background technique

Cutting fluid is a processing fluid used for cooling and lubricating during metal processing. It has various types and complex components. The common characteristics of cutting fluid wastewater are large oil content and strong stability, high content of organic matter, and poor biodegradability (that is, difficult to biodegrade). Commonly used treatment methods for cutting fluid wastewater include physical and chemical treatment, advanced oxidation, and biochemical methods.

(1) Physicochemical method

When treating cutting fluid wastewater, the physical and chemical treatment methods include adsorption method, membrane separation method, air flotation method, acid precipitation method, salt precipitation method, coagulation method, etc.

The adsorption method is to use the pores of porous solid substances to adsorb and remove pollutants such as colloidal particles, suspended organic matter and microorganisms in water. Commonly used adsorbents include activated carbon and macroporous resins. Activated carbon is expensive, and its adsorption capacity is limited, so it needs to be replaced frequently. The use of activated carbon will increase the treatment cost, so it is usually only used in the treatment of wastewater with low oil content or in advanced treatment. The adsorption equipment occupies a small area and has a good treatment effect, but the cost is high and the regeneration of the adsorbent is difficult.

Membrane separation method is to use filter membrane to intercept pollutants, so that wastewater can be purified. However, this method has strict requirements on the pretreatment of wastewater to avoid rapid fouling of the membrane and prolong the use time of the membrane. Membrane treatment method has high investment cost, strict operation and management requirements, membrane fouling and other problems, and membrane cleaning is troublesome, sometimes the concentration of organic matter in the filtrate is still relatively high, and subsequent biochemical treatment is required, and the treatment cost is high.

The air flotation method refers to the use of highly dispersed micro-bubbles to adhere to the pollutants containing hydrophobic groups in the wastewater, so that the small bubbles and pollutants are combined into a whole with a density lower than that of water, so that they float on the water surface and are removed. The air flotation effect can be improved by adding coagulant and other measures, and the wastewater with low organic content can be discharged, but most of them still need further advanced treatment. The amount of wastewater treated by the air flotation method is large, and no waste residue and waste gas will be generated, but the air flotation method occupies a large area and consumes high energy consumption.

Acid analysis method is a method of converting dissolved or colloidal oily substances into suspended state under acidic conditions, thereby separating oily substances, etc. from liquids. This type of method is easy to operate, and the agents used are generally concentrated sulfuric acid and nitric acid. For strong acidic substances such as waste acid, waste acid can also be used instead of pure acidic reagents, but this method produces more sediment or scum, and requires equipment to have certain corrosion resistance.

The salting out method is to add inorganic salts to the wastewater to a certain concentration to destroy the hydration film of the oil droplets. Commonly used electrolytes include calcium chloride, magnesium chloride, sodium chloride, calcium sulfate, aluminum potassium sulfate, etc. However, the salting-out method is usually not as effective as the acid-out method, and the dosage of the salt-out method is larger, the price is more expensive, and it will bring a large amount of sludge precipitation, which will bring great trouble to the treatment.

The coagulation method is to add a coagulant to the wastewater, and use the coagulant's net capture, adsorption and bridging effects to make the particulate oil droplets coalesce and become larger, and then use other conventional methods to achieve Solid-liquid separation and removal. There are three types of coagulants: inorganic coagulants, organic coagulants and microbial coagulants. The most commonly used inorganic coagulants are aluminum salts, iron salts and calcium chloride, and polyaluminum chloride (PAC), polyferric chloride, polyaluminum ferric chloride, and polyaluminum silicate developed on this basis. Iron and other inorganic polymer coagulants. There are many types of organic coagulants, which are generally divided into two categories: natural organic coagulants and synthetic organic coagulants. In terms of structure, there are three types: anionic, cationic and nonionic. Microbial coagulant is a new type of coagulant, which is a metabolite produced by microorganisms or their secretions. It is easy to separate solids and liquids, and the amount of sediment and mud formed is small, and it is easy to be degraded by microorganisms through their own metabolic reactions. Toxicity, no secondary pollution. Since the preparation of different types of microbial coagulants requires different conditions, and there are many influencing factors, such as the carbon source of the medium, nitrogen source, culture temperature, pH value, etc., the current microbial coagulants are too expensive due to their high production costs. Not yet widely used.

(2) Advanced Oxidation Method

Advanced oxidation methods generally include ozone oxidation, Fenton's reagent method, and the like. The most notable feature of the advanced oxidation method is that the system can generate a relatively high concentration of hydroxyl radicals. The oxidation-reduction potential of hydroxyl radicals is very high, and it can undergo redox reactions with most organic substances. Changes, so that the organic matter is finally degraded into small molecular substances such as carbon dioxide and water, so as to achieve the purpose of completely oxidizing the organic matter, and it is environmentally friendly and pollution-free. However, the efficiency of ozone dosing and contact reaction system in the ozonation method is low, so the amount of ozone dosing is large, and the device for preparing ozone has high power consumption and high cost, so the application of this method is limited. The application cost of hydrogen peroxide (H ₂ O ₂ ) used in the Fenton reagent method is relatively high, so the application is also limited.

(3) Biological treatment method

Biological treatment is a treatment method that uses microbial degradation to remove organic matter and other pollutants in wastewater. Since the removal of pollutants uses the biochemical reactions that occur during the life activities of microorganisms, it is often called biochemical method. According to the different requirements of microorganisms for oxygen in the process of biological wastewater treatment, biological methods are divided into aerobic biological treatment methods and anaerobic biological treatment methods.

(1) Aerobic biological treatment method is to supply microorganisms with sufficient oxygen during the treatment process, and use aerobic microorganisms to oxidize and decompose organic matter, and finally convert it into CO ₂ and water. Aerobic biological treatment processes mainly include activated sludge method and biofilm method (such as biological filter, biological turntable, biological contact oxidation, biological fluidized bed). This method has a good effect on the treatment of easily biodegradable wastewater, but it consumes a lot of energy, and it is difficult to treat and dispose of the remaining sludge.

(2) Anaerobic biological treatment method is to use anaerobic microorganisms to convert organic matter in wastewater into gases such as methane and carbon dioxide without supplying oxygen during the treatment process. The anaerobic biodegradation process of macromolecular organic matter can be divided into three stages: hydrolytic acidification stage (under the action of hydrolysis and fermentation bacteria, macromolecular organic matter is converted into monosaccharides, amino acids, fatty acids, glycerol, etc.), hydrogen production and acetic acid stage (under the action of hydrogen-producing acetogenic bacteria, the products of the first stage are converted into hydrogen, carbon dioxide and acetic acid) and the methanogenic stage (under the action of methanogenic bacteria, the products of the second stage are converted into gases such as methane) . The methane produced by the anaerobic biological treatment process can be reused as energy, and the amount of excess sludge produced is small. However, due to the slow growth and reproduction of anaerobic bacteria, which are sensitive to toxic substances and have strict requirements on the living environment, the anaerobic biological treatment process has high requirements for operation management and strict control of operating conditions, otherwise it is easy to cause anaerobic system collapse.

Utility model content

The purpose of the utility model is to overcome the deficiencies of the prior art and provide a device for coagulation-anaerobic hydrolysis-aerobic cooperative treatment of cutting fluid wastewater which is simple, easy to operate and manage, and low in cost.

The technical scheme of the utility model is summarized as follows:

A coagulation-anaerobic hydrolysis-aerobic co-processing device for cutting fluid wastewater, the water inlet pipe 11 is connected to the coagulation tank 1; the coagulation tank 1 is sequentially connected to the first sedimentation tank 2, the anaerobic hydrolysis tank 3, and the second sedimentation tank 2 through pipelines. Two sedimentation tanks 4, aerobic reaction tanks 5, and the water inlets of the third sedimentation tank 6 are connected; the bottom of the first sedimentation tank 2 is connected to the deposition floc discharge pipe 12; Pass 13, the first sludge return pump 15 is connected to the anaerobic hydrolysis tank 3, and the first tee 13 is connected to the first excess sludge discharge pipe 14; Pass 16, the second sludge return pump 18 is connected with the aerobic reaction tank 5 after being connected, the second tee 16 is connected with the second remaining sludge discharge pipe 17; the top of the third settling tank 6 is provided with an outlet pipe 19; The first agitator 7 is arranged inside the coagulation tank 1; the second agitator 8 is arranged inside the anaerobic hydrolysis tank 3; The device 10 is connected with the blast aerator 9 arranged outside the aerobic reaction tank 5 through a pipeline.

The utility model has the following beneficial effects:

The device and method of the utility model carry out coagulation pretreatment on the cutting fluid wastewater, which can not only separate the oil and water, remove most of the petroleum, but also remove some macromolecular organic pollutants, which can improve the biodegradability of the wastewater, and The required equipment is simple, and the operation management, operation and maintenance are convenient. The anaerobic hydrolysis biological treatment method does not supply oxygen during the treatment process, and only uses anaerobic microorganisms to control the anaerobic reaction in the hydrolysis and acidification stage of hydrolysis of macromolecular organic matter into small molecular organic matter, without the stage of hydrogen production and acetic acid production and methane production stage to improve the biodegradability of wastewater. Therefore, there is no need to cultivate methanogenic bacteria in the system, so the operating conditions are looser than the complete anaerobic biological treatment method for methanogenicity, and the operation management is more convenient than the anaerobic biological treatment method for methanogenicity. Aerobic synergistic reaction, glucose is added as a medicament for synergistic degradation of difficult biodegradation, and the cost is low.

The method of the utility model has the advantages of simple operation and convenient maintenance, and the dosing medicine is a common medicine in the water treatment industry, which is easy to purchase and low in price. After the cutting fluid wastewater is treated by this combination process, the concentration of organic matter, petroleum and other pollutants in the wastewater is greatly reduced. The method of the utility model treats the cutting fluid wastewater so that COD, BOD ₅ , petroleum, suspended solids and pH can meet the requirements of the C-level discharge standard in the "Water Quality Standards for Discharge of Sewage into Urban Sewers (GB/T31962-2015)".

Description of drawings

Fig. 1 is a schematic diagram of coagulation-anaerobic hydrolysis-aerobic co-processing of cutting fluid wastewater.

Fig. 2 is a schematic diagram of a coagulation-anaerobic hydrolysis-aerobic co-processing device for cutting fluid wastewater.

In the figure: 1—coagulation tank 2—first sedimentation tank 3—anaerobic hydrolysis tank 4—second sedimentation tank 5—aerobic reaction tank 6—third sedimentation tank 7—first stirring Device 8—second agitator 9—blast aerator 10—microporous aerator 11—water inlet pipe 12—deposited floc discharge pipe 13—first tee 14—first remaining Sludge discharge pipe 15—first sludge return pump 16—second tee 17—second excess sludge discharge pipe 18—second sludge return pump 19—outlet pipe

detailed description

Below in conjunction with accompanying drawing, the utility model is further described.

A coagulation-anaerobic hydrolysis-aerobic co-processing device for cutting fluid wastewater, see Figure 2, the water inlet pipe 11 is connected to the coagulation tank 1; Pool 3, the second sedimentation tank 4, aerobic reaction tank 5, and the water inlet of the third sedimentation tank 6 are connected; the bottom of the first sedimentation tank 2 is connected to the sedimentation floc discharge pipe 12; the bottom of the second sedimentation tank 4 is sequentially passed through the pipeline After being connected with the first three-way 13 and the first sludge return pump 15, it is connected with the anaerobic hydrolysis tank 3, and the first three-way 13 is connected with the first excess sludge discharge pipe 14; the bottom of the third sedimentation tank 6 passes through the pipeline in turn After being connected with the second three-way 16 and the second sludge return pump 18, it is connected with the aerobic reaction tank 5, and the second three-way 16 is connected with the second excess sludge discharge pipe 17; the upper part of the third sedimentation tank 6 is provided with an outlet Water pipe 19; a first agitator 7 is arranged inside the coagulation tank 1; a second agitator 8 is arranged inside the anaerobic hydrolysis tank 3; a microporous aerator 10 is uniformly arranged at the bottom of the aerobic reaction tank 5, The microporous aerator 10 is connected with the blast aerator 9 arranged outside the aerobic reaction tank 5 through a pipeline.

A coagulation-anaerobic hydrolysis-aerobic co-processing method for cutting fluid wastewater, as shown in Figure 1 and Figure 2, includes the following steps: (1) using a coagulation-anaerobic hydrolysis-aerobic co-processing device for cutting fluid wastewater , the device is: the water inlet pipe 11 is connected to the coagulation tank 1; the coagulation tank 1 is connected with the first sedimentation tank 2, the anaerobic hydrolysis tank 3, the second sedimentation tank 4, the aerobic reaction tank 5, the second sedimentation tank in turn through the pipeline The water inlet end of the third sedimentation tank 6 is connected; the bottom of the first sedimentation tank 2 is connected to the sedimentary floc discharge pipe 12; It is connected with the anaerobic hydrolysis tank 3, and the first three-way 13 is connected with the first excess sludge discharge pipe 14; the bottom of the third sedimentation tank 6 is connected with the second three-way 16 and the second sludge return pump 18 in sequence through pipelines It is connected with the aerobic reaction tank 5, and the second tee 16 is connected with the second excess sludge discharge pipe 17; the upper part of the third sedimentation tank 6 is provided with an outlet pipe 19; the first agitator 7 is provided inside the coagulation tank 1 ; The second agitator 8 is arranged inside the anaerobic hydrolysis tank 3; the microporous aerator 10 is uniformly arranged at the bottom of the aerobic reaction tank 5, and the microporous aerator 10 is arranged on the aerobic reaction tank through the pipeline. 5 external blast aerators 9 are connected;

(2) The cutting fluid waste water flows into the coagulation tank 1 from the water inlet pipe 11, and the coagulant polyaluminum chloride (PAC) and the coagulation aid polyacrylamide (PAM) are put into the coagulation tank 1, and the dosage of PAC is 9g/L, the dosage of PAM is 0.3g/L, under the action of the first agitator 7, most of the petroleum and some organic matter in the cutting fluid wastewater, PAC and PAM have a mixed flocculation reaction. The mixed solution flows into the first settling tank 2 and settles for 1 hour, and the flocs deposited at the bottom of the first settling tank 2 are discharged from the deposition floc discharge pipe 12; the first settling tank 2 supernatant enters the anaerobic hydrolysis tank 3, due to the Coagulation with PAM adsorbs a large amount of refractory polymer organic matter and petroleum substances in the cutting fluid wastewater, so after coagulation treatment, the petroleum and organic substances in the cutting fluid wastewater are significantly removed, and the supernatant of the first sedimentation tank 2 can be reduced The biochemical property (B/C value, that is, BOD ₅ /COD value) is significantly improved compared with the original wastewater; the return sludge from the second sedimentation tank 4 is pumped into the anaerobic hydrolysis tank 3 through the first sludge return pump 15, and the first sedimentation tank The pool supernatant and the anaerobic return sludge are mixed under the action of the second agitator 8, and a hydrolytic acidification reaction occurs in the anaerobic hydrolysis tank, and part of the macromolecular organic matter is hydrolyzed into a small molecular organic matter, thereby further improving the biodegradability of the wastewater. Since the anaerobic hydrolysis product has acidic substances, in order to prevent the pH of the mixed solution in the anaerobic hydrolysis tank from dropping too much and inhibit the activity of the anaerobic hydrolysis sludge, alkali is added to the anaerobic hydrolysis tank 3. On the other hand, due to the anaerobic hydrolysis The aerobic oxidation process of organic matter in the subsequent aerobic reaction tank will generate alkalinity, which will increase the pH of the mixed solution in the aerobic reaction tank, so adding alkali to the anaerobic hydrolysis tank will increase the pH of the mixed solution in the anaerobic hydrolysis tank. It can be between 7.0 and 7.5, and the alkali can be sodium hydroxide or sodium bicarbonate, which is economically available; The residence time is 24 hours; the mud-water mixture in the anaerobic hydrolysis tank flows into the second settling tank 4 and settles for 2 hours, and a part of the sludge at the bottom of the second settling tank 4 is pumped into the anaerobic hydrolysis tank 3 through the first sludge return pump 15, so that The sludge reflux ratio is 80% to 120%, and the other part is discharged through the first three-way 13 and the first excess sludge discharge pipe 14. The amount of sludge discharged should keep the sludge age of the activated sludge in the anaerobic hydrolysis tank at 30 days to 35 days; the supernatant of the second sedimentation tank 4 flows into the aerobic reaction tank 5, and at the same time, the return sludge from the third sedimentation tank 6 is pumped into the aerobic reaction tank 5 through the second sludge return pump 18. The air machine 9 is turned on, and oxygen is supplied to the aerobic reaction tank 5 through the microporous aerator 10, so that the dissolved oxygen concentration of the mixed solution is greater than 4.0 mg/L, and glucose is added to the aerobic reaction tank 5, and the glucose synergistically degrades partly difficult To degrade organic matter, the dosage of glucose is 2.0g/L; the concentration of suspended solids in the mixed liquid in the aerobic reaction tank 5 is 4000mg/L～6000mg/L, and the hydraulic retention time of the aerobic reaction tank is 36 hours; the supernatant of the second sedimentation tank Slurry-water mixed flow formed by liquid and aerobic return sludge After entering the third settling tank 6, settle for 2 hours, a part of the sludge at the bottom of the third settling tank 6 is pumped into the aerobic reaction tank 5 through the second sludge return pump 18, so that the sludge return ratio is 80% to 120%, and the other part Discharge through the second three-way 16 through the second excess sludge discharge pipe 17, and the sludge discharge should keep the sludge age of the activated sludge in the aerobic reaction tank at 10 days to 12 days; Outlet pipe 19 discharges.

Example 1

The cutting fluid wastewater discharged from a mechanical processing plant is operated through the method and parameters of the utility model. After the wastewater is treated, the COD, BOD ₅ , petroleum, suspended solids and pH all reach the "Water Quality Standard for Sewage Discharge into Urban Sewers (GB/T31962-2015 )" in the C-level emission standards. See columns 1-5 and column 7 in Table 1 for details.

In order to verify the synergistic degradation effect of glucose on refractory organic matter in cutting fluid wastewater, the method of the utility model is also adopted for the cutting fluid wastewater, only glucose is not added in the aerobic reaction tank, and the operating parameters of other units are the same as those in the utility model If they are the same, see the 6th column in Table 1 for the effluent water quality of the third sedimentation tank.

Comparing the data in columns 5 and 6 in Table 1, it can be seen that the synergistic degradation effect of glucose on refractory organic matter in cutting fluid wastewater is obvious, and adding glucose to the aerobic reaction tank can significantly improve the removal rate of organic matter.

Claims (1)

1. A coagulation-anaerobic hydrolysis-aerobic co-processing device for cutting fluid waste water, the water inlet pipe (11) is connected to the coagulation tank (1); it is characterized in that the coagulation tank (1) is connected to the first coagulation tank (1) sequentially through the pipeline The water inlets of sedimentation tank (2), anaerobic hydrolysis tank (3), second sedimentation tank (4), aerobic reaction tank (5), and third sedimentation tank (6) are connected; the first sedimentation tank (2) The bottom is connected to the sedimentary floc discharge pipe (12); the bottom of the second sedimentation tank (4) is connected with the first tee (13) and the first sludge return pump (15) through pipelines in turn, and then connected to the anaerobic hydrolysis tank (3 ) connection, the first three-way (13) is connected with the first excess sludge discharge pipe (14); the bottom of the third sedimentation tank (6) is connected with the second three-way (16) and the second sludge return pump in turn through the pipeline (18) is connected with the aerobic reaction tank (5) after being connected, and the second tee (16) is connected with the second excess sludge discharge pipe (17); the top of the third settling tank (6) is provided with an outlet pipe (19 ); the coagulation tank (1) is provided with the first agitator (7); the anaerobic hydrolysis tank (3) is provided with the second agitator (8); the bottom of the aerobic reaction tank (5) is uniform A microporous aerator (10) is provided, and the microporous aerator (10) is connected with the blast aerator (9) arranged outside the aerobic reaction tank (5) through a pipeline.