CN203187488U - System for treating DCP (dicalcium phosphate) wastewater - Google Patents

Abstract

The utility model discloses a system for treating DCP (dicalcium phosphate) wastewater. The system comprises a first level facultative tank used for performing first level facultative biochemical treatment on the DCP wastewater, a first level aerobic pool used for performing first level aerobic biochemical treatment on the discharge water of the first level facultative biochemical treatment, an optional catalytic oxidation pool used for performing catalytic oxidation treatment on the discharge water of the first level aerobic biochemical treatment, and a second level biochemical pool used for performing second level biochemical treatment on the discharge water of the first level aerobic biochemical treatment or the discharge water of the catalytic oxidation treatment if the catalytic oxidation pool exists. The treatment system provided by the utility model can be used for effectively treating the DCP wastewater without generating secondary pollution of H2S.

Description

Systems for treating DCP wastewater

technical field

The utility model relates to a treatment method and a treatment system for fine chemical production wastewater, more specifically to a treatment method and a treatment system for dicumyl peroxide (DCP) production wastewater.

Background technique

DCP is an organic peroxide crosslinking agent, mainly used as a crosslinking agent for various olefin polymers and copolymers (such as polyethylene, chlorinated polyethylene, silicone rubber, etc.) and a polymerization initiator for polystyrene , It can also be used as curing agent for unsaturated polyester resin. After DCP is crosslinked, the physical properties of the polymer are greatly improved, and the heat resistance, chemical resistance, pressure resistance, crack resistance and mechanical strength are all increased. DCP is widely used in wire and cable, shoemaking, building materials and other industries. In recent years, with the continuous expansion of the polymer material market, the demand for DCP has increased year by year, and the market potential is huge.

The industrial production of DCP is to use cumene as a raw material, react cumene hydroperoxide by oxidation to generate cumene hydroperoxide, and react part of cumene hydroperoxide to generate dimethyl benzyl alcohol by reduction, and then make dimethyl benzyl alcohol The condensation reaction between benzyl alcohol and cumene hydroperoxide produces DCP.

A large amount of wastewater is produced during the production of DCP, among which organic pollutants include cumene hydroperoxide, dicumyl perhydrogenated, cumene, acetophenone, benzyl alcohol, dimethyl sulfoxide, methyl styrene, Phenol (alkali dissolved in wastewater in the form of sodium phenate); inorganic pollutants include oxalic acid, ferrous sulfate, sodium sulfate, sodium sulfide, perchloric acid, and sodium thiosulfate.

The organic compounds in DCP wastewater have great harm and pollution to the human body and the environment, among which the harm of phenol is more prominent, and the high concentration of inorganic salts restricts the activity of microorganisms in the biochemical system.

At present, domestic high-concentration COD _Cr wastewater is mainly treated with the method of "anaerobic biochemistry + aerobic biochemistry + micro-electrolysis". COD _Cr removal rate, and finally use micro-electrolysis to treat organic matter that is difficult to degrade in biochemical processes.

However, for DCP production wastewater (hereinafter referred to as DCP wastewater), there are many problems in the treatment by the above-mentioned conventional methods because it contains high concentration of sulfide salts.

First of all, the sulfur contained in DCP wastewater will produce hydrogen sulfide during the anaerobic biochemical process, and hydrogen sulfide will volatilize into the air during the aerobic stage to cause secondary pollution. For example, after DCP wastewater is anaerobically treated in an upflow anaerobic sludge bed (UASB) reactor, the concentration of hydrogen sulfide in the wastewater can reach 300mg/L, resulting in secondary pollution to the surrounding environment.

Secondly, when the waste water contains a relatively high concentration of inorganic salts, the packing in the micro-electrolysis reactor will harden and affect the treatment effect.

Therefore, there is an urgent need for a method that can effectively treat DCP wastewater without causing secondary pollution.

Contents of the invention

In order to solve at least one problem in the above-mentioned prior art, the utility model provides a novel DCP wastewater treatment method and treatment system, wherein the "anaerobic biochemical" treatment in the prior art is replaced by "facultative biochemical" treatment Effectively eliminate the problem of hydrogen sulfide secondary pollution.

Therefore, on the one hand, the utility model provides the method for processing DCP waste water, and it comprises the steps:

1) performing primary facultative biochemical treatment on the DCP wastewater;

2) performing primary aerobic biochemical treatment on the effluent from step 1); and

3) Optionally, the effluent from step 2) is subjected to catalytic oxidation treatment, ozone treatment or membrane bioreactor (MBR) treatment.

Preferably, the pH value of the DCP wastewater is adjusted to 11±1 before step 1).

Preferably, in step 1), the oxidation-reduction potential (ORP) is controlled in the range of -150mv to 50mv, preferably in the range of -50mv to 50mv.

Preferably, in step 1), the concentration of dissolved oxygen (DO) is controlled within the range of 0.1-0.5 mg/L.

Preferably, in step 1), the concentration of mixed liquor suspended solids (MLSS) is controlled within the range of 3000-4000 mg/L.

Preferably, in step 1), the ratio of backflow water to inflow water is controlled to be 1.5:1.

Preferably, in step 2), the DO concentration is controlled in the range of 2.0-5.0 mg/L.

Preferably, in step 2), the MLSS concentration is controlled in the range of 2000-3000 mg/L.

Preferably, in step 2), the ratio of returned sludge to water inflow is controlled to be 1:1.

Preferably, in step 3), the effluent from step 2) is subjected to catalytic oxidation treatment. More preferably, the catalytic oxidation treatment is carried out using the Fenton reagent method, including using the Fenton reagent method alone or combining the Fenton reagent method with other methods, such as light-Fenton reagent method, electric-Fenton reagent method and coagulation-Fenton reagent method Law. Particularly preferably, the catalytic oxidation treatment is carried out by coagulation-Fenton method.

Preferably, in step 3) in the catalytic oxidation by the Fenton reagent method, the amount of ferrous sulfate added is 3-6 liters/ton of wastewater, and the amount of hydrogen peroxide added is 2-4 liters/ton of wastewater.

Preferably, the pH of the wastewater is controlled in the range of 2.5-3.5 during the catalytic oxidation process of the Fenton reagent method in step 3).

Preferably, step 3) is carried out using the coagulation-Fenton method, wherein the dosage of the coagulant is controlled within the range of 2-4 liters/ton of wastewater, and it is further preferred that the pH of the wastewater during the coagulation and sedimentation process is controlled at 7±0.5 scope.

In a preferred embodiment, the method of the present invention further includes the following steps: 4) performing secondary biochemical treatment on the effluent of step 2) or the effluent of step 3) if there is step 3). More preferably, the secondary biochemical treatment is carried out by a biofilm process, further preferably by a contact oxidation method, and particularly preferably includes a secondary facultative biochemical treatment and a secondary aerobic biochemical treatment.

On the other hand, the utility model provides a system for processing DCP wastewater, which includes:

A first-level facultative tank for DCP waste water to be treated with one-level facultative biochemical treatment;

The first-level aerobic pool for the first-level aerobic biochemical treatment of the effluent from the first-level facultative biochemical treatment;

Optional catalytic oxidation tank for catalytic oxidation treatment of primary aerobic biochemical treatment effluent; and

A secondary biochemical pool for secondary biochemical treatment of the effluent from the primary aerobic biochemical treatment or if there is a catalytic oxidation tank.

Preferably, a secondary coagulation sedimentation tank is also included between the catalytic oxidation tank and the secondary biochemical tank.

Preferably, a primary sedimentation tank is also included between the primary aerobic tank and the catalytic oxidation tank.

Further preferably, the primary sedimentation tank is also connected to the sludge return tank, and the sludge return tank is further connected to the primary aerobic tank to form a sludge return circuit.

Further preferably, the sludge reflux tank is connected to the primary aerobic tank through an air stripping reflux device.

Preferably, a primary coagulation sedimentation tank is also included between the primary sedimentation tank and the catalytic oxidation tank.

Preferably, the secondary biochemical pool includes a secondary facultative pool and a secondary aerobic pool.

Further preferably, a secondary sedimentation tank is included after the secondary aerobic tank.

Preferably, the aeration system for the primary facultative biochemical treatment, the aeration system for the primary aerobic biochemical treatment, and the optional aeration system for the catalytic oxidation treatment are connected to the same blower.

After being treated by the method/system of the present utility model, the effluent quality of DCP wastewater can meet the requirements of Shanghai Wastewater Discharge Standard "DB31/199-2009". And, compared with the prior art, the utility model method can also achieve at least one of the following beneficial effects:

1. The secondary pollution of hydrogen sulfide is avoided by using facultative biochemical treatment instead of aerobic biochemical treatment;

2. Secondary biochemical treatment can be used instead of micro-electrolysis treatment, so as to avoid various problems caused by micro-electrolysis treatment.

Description of drawings

Preferred embodiments of the present utility model will be described below in conjunction with the accompanying drawings, wherein:

Figure 1: A schematic diagram of a DCP wastewater treatment system in a preferred embodiment of the present invention, wherein the dotted line indicates that the catalytic oxidation tank is optional and can be selected according to actual needs.

Fig. 2: A schematic diagram of a DCP wastewater treatment system in a particularly preferred embodiment of the present invention.

Detailed ways

In order to better understand the technical solutions and beneficial effects of the utility model, preferred implementations of the utility model are described in more detail below in conjunction with the accompanying drawings and examples. It should be understood that these illustrations are only exemplary, and should not be construed as limiting the utility model in any way.

As mentioned above, in the first aspect of the present invention, there is provided a combined method for treating DCP wastewater, which is characterized by comprising a first facultative biochemical treatment step and a first aerobic biochemical treatment step.

Optionally, after the primary aerobic biochemical treatment, the method of the present invention may further include a step of catalytic oxidation treatment, ozone treatment or MBR treatment on the aerobic treatment effluent, preferably using a catalytic oxidation treatment step.

Preferably, after the primary aerobic biochemical treatment or after the above optional step if there is such an optional step, the method of the present invention further includes the step of performing secondary biochemical treatment on the treated effluent.

Referring to Fig. 1, in a second aspect of the present invention, a system for processing DCP wastewater is provided, which includes:

A first-level facultative tank for DCP waste water to be treated with one-level facultative biochemical treatment;

The first-level aerobic pool for the first-level aerobic biochemical treatment of the effluent from the first-level facultative biochemical treatment;

Optional catalytic oxidation tank for catalytic oxidation treatment of primary aerobic biochemical treatment effluent; and

A secondary biochemical pool for secondary biochemical treatment of the effluent from the primary aerobic biochemical treatment or if there is a catalytic oxidation tank.

Preferably, a primary sedimentation tank is also included between the primary aerobic tank and the catalytic oxidation tank, more preferably the primary sedimentation tank is also connected to a sludge return tank for returning part of the sludge to the primary aerobic tank.

In some preferred embodiments, the first-stage aerobic sludge return method is to use aeration air for airlift return, eliminating the use of pneumatic diaphragm pumps for sludge transportation.

In some preferred embodiments, the aeration system of the first-level facultative biochemical treatment, the first-level aerobic biochemical treatment, and the catalytic oxidation treatment are kept at the same level as the waste water level, so that one blower can be used to simultaneously Aerobic and catalytic oxidation gas supply, saving sewage investment and power consumption.

In order to better understand the utility model, each processing step involved in the method of the utility model will be discussed in more detail below.

Primary facultative biochemical treatment

The primary facultative biochemical treatment mainly uses the metabolism of facultative microorganisms to convert the macromolecular organic matter in the wastewater into low molecular fatty acids, so as to realize the hydrolysis and acidification of the wastewater, thereby improving the biodegradability of the wastewater, and at the same time avoiding the high Concentrated sulfide salts are reduced to produce hydrogen sulfide during the biochemical treatment.

Since DCP wastewater contains high concentrations of sulfide and other organic matter, it is preferable to control its pH value at 11±1 before entering the first-level facultative treatment to ensure the stable operation of the biochemical system, and at the same time control the pH of the treated effluent to not be lower than 6.0.

During the primary facultative biochemical treatment process, the aeration rate can be controlled by monitoring the ORP to suppress the generation of hydrogen sulfide while improving the hydrolysis and acidification capacity. It is preferable to control the ORP in the range of -150mv to 50mv. When the ORP is lower than the above range, the treatment process is more anaerobic, resulting in increased hydrogen sulfide production; while when the ORP is higher than the above range, the treatment process is more aerobic, resulting in a decrease in hydrolysis and acidification capacity.

In addition, in order to obtain the best effect of facultative oxygen treatment, it is particularly preferred to control the DO concentration to 0.1-0.5 mg/L, the MLSS concentration to 3000-4000 mg/L, and the reflux water ratio to be 1.5:1.

Primary Aerobic Biochemical Treatment

The primary aerobic biochemical treatment mainly uses aerobic bacteria in activated sludge to complete the degradation of organic matter, so as to remove biodegradable organic matter in wastewater through oxidation.

In order to obtain the best aerobic treatment effect, it is particularly preferred to control DO concentration at 2.0-5.0 mg/L, MLSS concentration at 2000-3000 mg/L, and return sludge ratio of 1:1.

catalytic oxidation treatment

The residual organic matter in wastewater after primary aerobic biochemical treatment contains biorefractory substances (sometimes even mainly biodegradable substances), and their biodegradability is poor (sometimes even BOD ₅ /COD _Cr <0.1). The catalytic oxidation step can remove these biodegradable substances in the wastewater, further degrade the COD _Cr in the wastewater, and improve the biodegradability of the wastewater, which is beneficial to the subsequent biochemical treatment; on the other hand, the catalytic oxidation treatment can also remove Biocolor produced during biochemical treatment.

Preferably, Fenton's reagent is used to carry out the above catalytic oxidation treatment. For ease of understanding, some brief introductions to Fenton's reagent are given below.

1. The principle of Fenton's reagent

Fenton's reagent is a general term for the oxidation system composed of hydrogen peroxide and catalyst Fe ²⁺ . Under the catalysis of Fe ²⁺ ions, the decomposition activation energy of H ₂ O ₂ is low (34.9 kJ/mol), which can decompose and generate hydroxyl radical OH·, which is an effective factor for oxidizing organic matter.

2. Influencing factors of Fenton's reagent

As mentioned above, OH is an effective factor for Fenton's reagent to oxidize organic matter, while [Fe ²⁺ ], [H ₂ O ₂ ], [OH], etc. determine the production of OH, thus determining the degree of reaction between Fenton's reagent and organic matter . Usually, the factors affecting the treatment of refractory and refractory organic wastewater by Fenton reagent include pH value, H ₂ O ₂ dosage and catalyst dosage, etc.

2.1 pH value

Fenton's reagent can only work under acidic pH conditions. In neutral and alkaline environments, Fe ²⁺ cannot catalyze H ₂ O ₂ to produce OH·. According to the classic Fenton reagent reaction theory, the increase of pH value not only inhibits the generation of OH·, but also causes Fe ²⁺ in the solution to precipitate in the form of hydroxide and lose its catalytic ability. When the pH value is too low, the concentration of H ⁺ in the solution is too high, Fe ³⁺ cannot be successfully reduced to Fe ²⁺ , and the catalytic reaction is hindered. That is, the change of pH directly affects the complexing equilibrium system of Fe ²⁺ and Fe ³⁺ , thus affecting the oxidation ability of Fenton's reagent.

Therefore, in the method of the present invention, when the primary aerobic effluent enters the catalytic oxidation, it is preferable to firstly add sulfuric acid to adjust the pH value. In particular, the inventors of the present application have found through a large number of experiments that for the DCP wastewater treatment method of the present invention, when the pH value is controlled in the range of 2.5-3.5, Fenton's reagent has the best degradation effect on organic matter.

2.2 H ₂ O ₂ dosage

The effectiveness and economy of using Fenton's reagent to treat wastewater mainly depend on the dosage of H ₂ O ₂ . Generally, as the amount of H ₂ O ₂ increases, the degradation of organic matter first increases and then decreases.

The inventors of the present application have found through a large number of tests that for the DCP wastewater treatment method of the present invention, the Fenton reagent has the best degradation effect on organic matter when the dosage of hydrogen peroxide is controlled in the range of 2-4 liters/ton of wastewater.

2.3 Catalyst dosage

FeSO ₄ ·7H ₂ O is the most commonly used catalyst to catalyze the decomposition of H ₂ O ₂ to generate hydroxyl radical OH·. Same as H ₂ O ₂ , in general, with the increase of Fe ²⁺ dosage, the removal of COD in wastewater increases first, and then shows a downward trend. The reason is: when the concentration of Fe ²⁺ is low, the concentration of Fe ²⁺ increases, and the OH produced per unit amount of H ₂ O ₂ increases, and all the OH produced participates in the reaction with organic matter; when Fe ²⁺ When the concentration is too high, part of H ₂ O ₂ will decompose ineffectively and release O ₂ .

The inventors of the present application have found through a large number of tests that for the DCP wastewater treatment method of the present utility model, the Fenton reagent has the best degradation effect on organic matter when the dosage of ferrous sulfate is controlled in the range of 3-6 liters/ton of wastewater.

3. Combination of Fenton's reagent with other methods

In the method of the present invention, the Fenton reagent method can be used alone or in combination with other methods. Preferably, in order to further improve the removal effect of organic matter, based on the standard Fenton reagent, by changing and coupling the reaction conditions, the reaction mechanism is improved, and a series of Fenton-like reagent methods with similar mechanisms are obtained, such as light-Fenton reagent method, electric -Fenton's reagent method and coagulation-Fenton's reagent method, etc.

3.1 Light-Fenton method

3.1.1 UV-Fenton method

When there is light radiation (such as ultraviolet light, visible light), the oxidation performance of Fenton's reagent is greatly improved. The UV-Fenton method is also called the light-assisted Fenton method, which is a combination of the ordinary Fenton system and the UV-H ₂ O ₂ system. Compared with the two systems alone, its advantage is that it reduces the amount of Fe ²⁺ and increases the amount of H _{2 O2} utilization. This is due to the synergistic effect of Fe ³⁺ and ultraviolet light on the catalytic decomposition of H ₂ O ₂ . The main problem of this method is that the utilization rate of solar energy is still not high, the energy consumption is relatively large, and the cost of processing equipment is relatively high.

3.1.2 UV-vis iron oxalate complex H ₂ O ₂ method

When the concentration of organic matter is high, the number of light quanta absorbed by the Fe ³⁺ complex is very small, and a longer irradiation time is required, and the dosage of H ₂ O ₂ also increases accordingly, and OH· is easily absorbed by high-concentration H ₂ O ₂ cleared. Therefore, the UV-Fenton method is generally only suitable for treating low-concentration organic wastewater. When substances with high photochemical activity (such as oxalate and citrate complexes containing Fe ³⁺ ) are introduced into the UV-Fenton system, the utilization effect of ultraviolet and visible light can be effectively improved.

3.2 Electro-Fenton method

The light-Fenton method improves the degree of mineralization of organic matter compared with the common Fenton method, but it still has the disadvantages of low photon quantum efficiency and imperfect automatic H2O2 generation mechanism. The so-called mineralization refers to the conversion of organic pollutants into minerals, such as water, carbon dioxide and inorganic salts. Mineralization treatment of organic wastewater technology is to use additives and accelerators to generate a certain amount of energy to destroy the chemical bonds of pollutant molecules, so that the pollutant molecules are broken and changed from large to small, and finally the carbon in the pollutant molecules is converted into carbon dioxide, nitrogen and Phosphorus and other pollutants are converted into inorganic salts, which completely degrades organic substances in wastewater, thereby eliminating pollutants, reducing COD and ammonia nitrogen values in industrial wastewater, and finally improving water quality to meet discharge requirements.

Electro-Fenton method utilizes H ₂ O ₂ and Fe ²⁺ produced by electrochemical method as the continuous source of Fenton reagent. Compared with photo-Fenton method, it has the following advantages: first, the mechanism of automatic generation of H ₂ O ₂ is relatively complete; There are many factors that lead to the degradation of organic matter (in addition to the oxidation of hydroxyl radicals, there are also anodic oxidation, electrosorption, etc.). Since the cost of H ₂ O ₂ is much higher than that of Fe ²⁺ , it is of great practical significance to introduce the mechanism of automatic generation of H ₂ O ₂ into the Fenton system by electrochemical method.

3.3 Coagulation-Fenton method

Fenton's reagent oxidatively degrades organic matter and also undergoes oxidative coupling reactions, and the coupled macromolecules are removed by coagulation, thus obtaining the coagulation-Fenton method. The coagulation method is effective for hydrophobic pollutants, and the Fenton reagent oxidation method has a good effect on the treatment of water-soluble substances, and the low-dose Fenton reaction can reduce the water solubility of organic matter, which is helpful for coagulation, so the coagulation-Fenton method is in Good treatment effect can be achieved when treating refractory biodegradable wastewater.

The inventors of the present application conducted experimental comparisons using different Fenton reagent methods and found that the coagulation-Fenton method has the best effect on the removal of pollutants from DCP wastewater, especially when treating primary aerobic biochemical effluent.

Preferably, liquid caustic soda (sodium hydroxide) and polyacrylamide (PAM) are used as coagulants in the coagulation-Fenton method used in the present invention. Alternatively, alternative liquid caustic soda such as ferrous sulfate, ferric chloride, aluminum sulfate and calcium hydroxide can also be used.

In addition, the inventors of the present application have found through a large number of tests that for the DCP wastewater treatment method of the present utility model, when the dosage of coagulant is controlled in the range of 2-4 liters/ton of wastewater, the organic matter removal effect is the best. In particular, it is preferable to control the pH of the coagulation sedimentation tank within the range of 7±0.5 to facilitate coagulation.

In a specific embodiment, the coagulation-Fenton method of the present invention is carried out in the following manner: when the primary aerobic effluent enters the catalytic oxidation, first add sulfuric acid to adjust the pH, then add hydrogen peroxide and ferrous sulfate at the same time, and react through aeration Then add liquid caustic soda to adjust the pH, and then add polyacrylamide and ferrous sulfate. It is determined by experiments that the COD removal rate of wastewater can reach 15-25% after catalytic oxidation treatment.

In addition, the inventors used ozone and MBR instead of Fenton's reagent to test DCP wastewater treatment, and found that under the premise of ensuring that the treated effluent meets the standard, using ozone and MBR can replace Fenton's reagent for DCP wastewater treatment. However, considering that the operating cost of ozone treatment is high, and the equipment investment of MBR treatment is too high, it is preferred to use Fenton's reagent to catalyze the oxidation treatment step.

secondary biochemical treatment

After the primary aerobic biochemical treatment and/or catalytic oxidation treatment steps, the COD in DCP wastewater has basically reached the standard. At this time, if necessary, methods such as flocculation or secondary biochemical treatment can be used to further reduce the suspended solids (SS) Concentration, in order to reduce the amount of chemical reagents, it is preferable to adopt secondary biochemical treatment.

The secondary biochemical treatment can further remove the remaining organic compounds in the wastewater while reducing the concentration of SS, so that the treated effluent can be discharged stably up to the standard. Preferably, the secondary biochemical treatment is carried out by a biofilm process, more preferably by a contact oxidation method, and particularly preferably includes a secondary facultative biochemical treatment and a secondary aerobic biochemical treatment.

Example

The utility model will be described in more detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments are only illustrative and do not constitute any form of limitation to the utility model.

general steps

Referring to Figure 2, DCP production wastewater can be divided into two streams after cleaning and diversion: concentrated wastewater and dilute wastewater. Concentrated wastewater and dilute wastewater are first adjusted for water quality and quantity respectively. For high-concentration production accident wastewater, pre-catalyzed oxidation treatment is performed first, and then the first-level biochemical treatment is carried out together to degrade organic matter in wastewater through microbial action. Then, according to the needs, the wastewater can be selected for catalytic oxidation treatment. Through the catalytic oxidation treatment, the degradation of organic matter in the wastewater can be achieved while improving the water quality of the wastewater and improving the biochemical properties of the wastewater. Finally, the wastewater enters the secondary biochemical treatment system to achieve the final degradation of organic matter in the wastewater and stabilize the water quality. Among them, the primary biochemical treatment mainly adopts the "facultative + aerobic" activated sludge method; the catalytic oxidation adopts the catalytic oxidation technology using Fenton's reagent as the oxidant; the secondary biochemical process adopts the biofilm process (contact oxidation). The treated wastewater will be brought into the sea discharge pipe network after reaching the Shanghai Municipal Wastewater Discharge Standard "DB31/199-2009".

After the secondary biochemical treatment, the physical and chemical sludge and biochemical sludge can be collected into the mud collection well through separate pipelines, and then lifted to the physical and chemical sludge thickening tank and biochemical sludge thickening tank through the sludge lifting pump. The frame filter press is used for dehydration treatment, and the dried sludge is disposed of by a qualified unit.

Example 1

According to the liquid level of the dilute wastewater regulating tank, use the lifting pump to balance the wastewater to the facultative pool, control the pH of the incoming water at 11±1, turn on the return pump to control the return water ratio of 1.5:1, and adjust the air volume of the fan to make the facultative pool in the facultative state State, control DO concentration: 0.1-0.5mg/L, MLSS concentration: 3000-4000 mg/L, ORP: -50-+50mv. Set up a sedimentation area before the first-level aerobic upflow of wastewater to the outlet to reduce the loss of microorganisms in the aerobic effluent.

The effluent from the facultative tank then enters the primary aerobic tank, where the aerobic bacteria in the activated sludge are used to complete the degradation of organic matter. Adjust the air volume to control the DO concentration in the primary aerobic pool: 2.0-5.0 mg/L, and the MLSS concentration: 2000-3000 mg/L. After the primary aerobic tank, a separate sedimentation tank and sludge return system are set up. Sedimentation in the sedimentation tank can reduce the SS concentration and improve the efficiency of subsequent treatment. Open the air valve of the sludge return tank to lift the sludge back to the first-level aerobic tank to control the return sludge ratio of 1:1.

The effluent from the primary aerobic pool passes through the primary sedimentation tank and the primary coagulation sedimentation tank, and then directly enters the secondary biochemical pool without catalytic oxidation treatment. The secondary biochemical pool is treated by contact oxidation method, and further includes the secondary facultative pool and secondary aerobic pool. After the secondary aerobic tank, a secondary sedimentation tank is set up to separate the muddy water from the secondary aerobic effluent, and the effluent from the secondary sedimentation tank meets the Shanghai secondary discharge standard.

The COD data of DCP production wastewater after each treatment step are recorded in Table 1.

Table 1 DCP production wastewater treatment effect table

The preferred embodiments of the present utility model have been specifically described above with reference to the accompanying drawings and examples, but these descriptions are only illustrative and not restrictive. Those skilled in the art can make various obvious changes and modifications to these preferred embodiments without departing from the spirit and scope of the present invention, and these changes or modified embodiments still fall within the protection scope of the present invention .

Claims (9)

1. handle the system of DCP waste water, it is characterized in that described system comprises:

DCP waste water is carried out the one-level oxygen compatibility pool that the one-level facultative anaerobic biochemical is handled;

The one-level facultative anaerobic biochemical is handled water outlet carry out the one-level Aerobic Pond that the one-level aerobic biochemical is handled;

Optional handles the catalyzed oxidation pond that catalytic oxidation treatment is carried out in water outlet to the one-level aerobic biochemical; With

The words that the one-level aerobic biochemical is handled water outlet or had the catalyzed oxidation pond are carried out the secondary biochemical pond of secondary biochemical treatment to the catalytic oxidation treatment water outlet.

2. according to the system of claim 1, it is characterized in that between catalyzed oxidation pond and secondary biochemical pond, also comprising the two-stage coagulation settling tank.

3. according to the system of claim 1 or 2, it is characterized in that between one-level Aerobic Pond and catalyzed oxidation pond, also comprising the one-level settling tank.

4. according to the system of claim 3, it is characterized in that the one-level settling tank is also connected to the mud backflow pool, this mud backflow pool is connected to the one-level Aerobic Pond, constitutes the mud reflux circuit.

5. according to the system of claim 4, it is characterized in that linking to each other by the air lift reflux between mud backflow pool and the one-level Aerobic Pond.

6. according to the system of claim 5, it is characterized in that between one-level settling tank and catalyzed oxidation pond, also comprising the one-level coagulative precipitation tank.

7. according to each system among the claim 1-2, it is characterized in that the secondary biochemical pond comprises secondary oxygen compatibility pool and secondary Aerobic Pond.

8. according to the system of claim 7, it is characterized in that after the secondary Aerobic Pond, also comprising second-level settling pond.

9. according to each system among the claim 1-2, it is characterized in that the aerating system of aerating system that the one-level facultative anaerobic biochemical handles, aerating system that the one-level aerobic biochemical is handled and optional catalytic oxidation treatment is connected with same typhoon machine.

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