CN111410359A - A pretreatment optimized operation process for high influent nitrogen and phosphorus concentration sewage treatment plant - Google Patents

Abstract

The invention provides a pretreatment optimized operation process for a high influent nitrogen and phosphorus concentration sewage treatment plant, which belongs to the field of high influent nitrogen and phosphorus concentration sewage treatment. In water treatment, the lifting process is carried out by the lifting pump, the sewage enters the flocculation reaction channel process, and the sewage enters the primary sedimentation tank with the water flow, and the sewage is discharged to the sludge storage tank process and the drainage and effluent treatment. The fine grating of the present invention adopts the inner inflow orifice grille, which can effectively remove the fine particles such as hair and cotton wool in the sewage, so as to prevent these substances from entering the subsequent system and affecting the operation of the equipment; The turning action can realize the mixing of sewage and chemicals, which replaces the traditional mechanical mixing and saves power consumption; because the sludge deposited in the primary sedimentation tank still has some small garbage, in order to reduce the clogging frequency of the sludge pump, the The mud pump is selected as a cutting pump with an inner cutting head.

Description

A pretreatment optimized operation process for high influent nitrogen and phosphorus concentration sewage treatment plant

technical field

The invention belongs to the technical field of high influent nitrogen and phosphorus concentration sewage treatment technology, and particularly relates to a pretreatment optimized operation process for a high influent nitrogen and phosphorus concentration sewage treatment plant.

Background technique

The optimized operation process of pretreatment is designed for sewage treatment plants with high influent nitrogen and phosphorus concentration. It aims to reduce the nitrogen and phosphorus content entering the biochemical system from the source through the addition and operation of this process, thereby reducing the investment of methanol and phosphorus removal agent. Increase the amount, and finally realize the low-cost and high-efficiency operation of the sewage plant.

In the arid and water-deficient areas in Northwest China, where residents save water, the drought and less rainfall, and the urban septic tanks are not cleaned up in time, the total nitrogen and total phosphorus concentrations in the influent of the sewage treatment plant can be as high as 130 mg/l (total nitrogen) and 12 mg/l. (Total Phosphorus), much higher than other sewage treatment plants in other regions (60-80mg/l and 5mg/l respectively). In recent years, the environmental protection department has become increasingly strict with the control of total nitrogen and total nitrogen in the effluent of sewage treatment plants, and it is mandatory for sewage treatment plants to install a total nitrogen and total phosphorus online instrument to monitor and monitor the total nitrogen and total phosphorus in the effluent throughout the day.

The influent of domestic sewage plants generally has the characteristics of high nitrogen and phosphorus concentration and low COD concentration. According to the removal principle of total nitrogen in sewage, if the effluent is to meet the standard stably, a large amount of carbon source (commonly methanol) needs to be added to the anoxic zone in the biochemical tank or the deep-bed denitrification filter of advanced treatment. The total phosphorus removal capacity of the biochemical system is limited. In order to ensure that the total phosphorus in the effluent reaches the standard, a large amount of phosphorus removal agent needs to be added. The dosage of methanol and phosphorus removal agent has a linear relationship with the total nitrogen and total phosphorus concentration in the influent, which brings great pressure on the operation cost of sewage treatment plants with high influent nitrogen and phosphorus concentration.

The optimized operation process of pretreatment is formed by optimizing the traditional pretreatment process based on the characteristics that most of the nitrogen and phosphorus in the influent of the sewage treatment plant with high influent nitrogen and phosphorus concentration are fine particles such as organic manure entrained by the sewage. The addition and operation of this process can reduce the amount of nitrogen and phosphorus entering the biochemical treatment system from the source to a certain extent, thereby reducing the dosage of methanol and phosphorus removal agent, and realize the low-cost and high-efficiency operation of the sewage treatment plant.

However, the existing sewage treatment process has the problems that if the treatment is not clean, it is easy to block the equipment, the waste of resources is serious, and the total amount of nitrogen and phosphorus in the biochemical system after treatment is still large.

Therefore, it is very necessary to invent a pretreatment optimized operation process for sewage treatment plants with high influent nitrogen and phosphorus concentration.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned technical problems, the present invention provides a pretreatment optimized operation process for high influent nitrogen and phosphorus concentration sewage treatment plants, so as to solve the problems of unclean treatment and easy clogging of equipment, serious waste of resources and biochemical changes after treatment in the existing sewage treatment process. There are still many problems in the total amount of nitrogen and phosphorus in the system. A pretreatment optimization operation process for a sewage treatment plant with high influent nitrogen and phosphorus concentration specifically includes the following steps:

Step 1: Prepare water for influent water treatment, discharge domestic sewage and wastewater from sewage treatment plants with high influent nitrogen and phosphorus concentration into the adjustment tank through the municipal pipe network. The domestic sewage contains a large amount of feces, paper scraps, pathogens, and suspended solids. -350mg/L, the organic matter concentration CODCr is between 100-400mg/L, and the suspended organic matter concentration BOD5 is 50-200mg/L;

Step 2: The lifting process is carried out by the lifting pump, and the sewage is lifted from the regulating tank to the fine grid channel and the flocculation reaction tank after being acted by the lifting pump. The grille set in the flocculation reaction tank blocks impurities, and at the same time, the blocked impurities are automatically scraped and sent into the grille, and the fine garbage and floating objects are also removed through the fine grille, and regular cleaning work is carried out;

Step 3: The sewage enters the flocculation reaction channel process, and the specific operation steps are as follows:

Step 1: Add flocculant to the baffle flocculation channel, and fully stir and mix by stirring rod;

The second step: the fine particles in the sewage and the colloidal substances in the water are fully mixed with the agent, and the bonded impurities can be salvaged through the salvage net to take out the floating objects;

Step 3: After the flocculation reaction tank is added with a coagulant aid, the small suspended solids in the sewage become larger. In the subsequent flocculation reaction tank, the liquid medicine continues to react, and the suspended particles continue to increase to form large sewage. mud, and prepare for the subsequent decontamination process;

Step 4: The sewage enters the primary sedimentation tank with the water flow, and the specific operation steps are as follows:

The first step: separation of sewage and sludge, using biofilm to separate the purified water and activated sludge from solid-liquid; biofilm can intercept activated sludge and most of the suspended solids, obtain clear water, and prepare for external use. Row;

The second step: the supernatant overflows from the water outlet at the upper part of the primary sedimentation tank and is left to the biochemical treatment system, which is sterilized by the pre-installed disinfectant in the biochemical treatment system, and stirred by the stirring mechanism in the biochemical treatment system to prepare for extraction. treated water;

Step 5: The process of discharging sewage and introducing mud to the mud storage tank, the specific operation steps are as follows:

Step 1: Sludge is deposited at the bottom of the pool. At this time, activated carbon carbon balls can be used to adsorb impurities and fine impurity particles in the sludge, and at the same time, activated sludge can be used to remove biodegradable organic pollutants in the water;

The second step: the bottom of the pool and the bottom of the sludge pool are connected with the diversion process, in which an activated carbon layer can be set at the middle connection part, which can adsorb impurities and bacteria at the connection;

Step 3: The sludge is lifted to the sludge storage tank through the action of the sludge pump, and the sludge can be temporarily stored through the sludge storage tank. At the same time, the disinfectant can be injected again for disinfection to remove bacteria, and then the impurities and larger dirt can be picked up;

Step 6: Drainage and effluent treatment, after disinfection treatment, direct discharge.

Preferably, in step 2, a plurality of grids formed in series are arranged inside the fine grid channel.

Preferably, in step 2, the fine grid adopts an inner inflow orifice grid.

Preferably, in step 2, more than two cobblestone layers are laid on the inner bottom of the flocculation reaction tank.

Preferably, in step 2, a baffle can also be installed behind the fine grid channel.

Preferably, in the third step, the salvage net in the second step adopts a trumpet-shaped stainless steel net with a hole diameter of 5 mm to 8 mm.

Preferably, in the fourth step, the biological membrane in the first step is a multi-layer hollow fiber membrane.

Preferably, in step 4, chlorine is used as the disinfectant in the second step.

Preferably, in step 5, the sludge pump in the third step is a cutting pump with an inner cutting head.

Compared with the prior art, the present invention has the following beneficial effects: because the pretreatment optimized operation process for high influent nitrogen and phosphorus concentration sewage treatment plants of the present invention is widely used in the technical field of high influent nitrogen and phosphorus concentration sewage treatment. The fine grid of the present invention adopts the inner inflow orifice grid, which can effectively remove fine particles such as hair and cotton wool in the sewage, so as to prevent these substances from entering the subsequent system and affecting the operation of the equipment; The turning action can realize the mixing of sewage and chemicals, replacing the traditional mechanical mixing, saving power consumption; adding flocculant and coagulant to the effluent of the grid, forming the fine suspended solids in the water into lumpy sludge, these sludges Through the action of the sludge pump, it is directly transported to the mud storage tank, and then directly dehydrated to form a mud cake for outbound treatment; most of these fine particles in the influent water are particles such as dilute manure flushed out of the septic tank, and nitrogen and phosphorus in the sewage The main source; through this operation, the total amount of nitrogen and phosphorus entering the biochemical system is reduced from the source; in the present invention, there is still some fine garbage due to the sludge precipitated in the primary sedimentation tank, in order to reduce the blocking frequency of the sludge pump, the sludge pump It is selected as a cutting pump with an inner cutting head; this is also a prominent point compared with the conventional sewage treatment pretreatment process, which improves the sewage treatment effect.

Description of drawings

Figure 1 is a process flow diagram of the pretreatment optimization operation for a high influent nitrogen and phosphorus concentration sewage treatment plant.

Figure 2 is a flow chart of the process of sewage entering the flocculation reaction channel.

Fig. 3 is the flow chart of the sewage entering the primary sedimentation tank with the water flow.

Fig. 4 is a flow chart of the process of discharging sewage and introducing mud to the mud storage tank.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings:

In the picture:

As shown in Figure 1

A pretreatment optimization operation process for a sewage treatment plant with high influent nitrogen and phosphorus concentration specifically includes the following steps:

S101: Prepare water for influent water treatment, and discharge domestic sewage and wastewater from sewage treatment plants with high influent nitrogen and phosphorus concentration into the adjustment tank through the municipal pipe network. The domestic sewage contains a large amount of feces, paper scraps, pathogens, and suspended solids. 350mg/L, the organic matter concentration CODCr is between 100-400mg/L, and the suspended organic matter concentration BOD5 is 50-200mg/L;

S102: The lifting process is carried out by the lifting pump, and the sewage is lifted from the regulating tank into the fine grid channel and the flocculation reaction tank after being acted by the lifting pump. The grille set in the reaction tank blocks impurities, and at the same time, the blocked impurities are automatically scraped up and sent into the grille, and the fine garbage and floating objects are also removed through the fine grille, and regular cleaning work is carried out;

S103: the sewage enters the flocculation reaction channel process, as shown in Figure 2, and the specific operation steps are as follows:

S301: Add flocculant to the baffle flocculation channel, and fully stir and mix by stirring rod;

S302: The fine particles in the sewage and the colloidal substances in the water are fully mixed with the chemicals, and the bonded impurities can be salvaged through the salvage net to take out the floating objects;

S303: After adding a coagulant at the rear end of the flocculation reaction tank, the fine suspended solids in the sewage become larger. In the subsequent flocculation reaction tank, the liquid medicine continues to react, and the suspended particles continue to increase in size to form large sludge. Prepare the follow-up decontamination process;

S104: enter the sewage into the primary sedimentation tank with the water flow, as shown in Figure 3, and the specific operation steps are as follows:

S401: Separation of sewage and sludge, using biofilm to separate the purified water and activated sludge from solid-liquid; biofilm can intercept activated sludge and most of the suspended solids, obtain clear water, and prepare for discharge;

S402: The supernatant overflows from the water outlet at the upper part of the primary sedimentation tank and is left in the biochemical treatment system, and is disinfected by the pre-installed disinfectant in the biochemical treatment system, and stirred by the stirring mechanism in the biochemical treatment system, ready to be extracted after treatment of clean water;

S105: the process of discharging sewage and introducing mud to the mud storage tank, as shown in Figure 4, the specific operation steps are as follows:

S501: The sludge is deposited at the bottom of the pool. At this time, the activated carbon carbon balls can be used to adsorb impurities and fine impurity particles in the sludge, and at the same time, the biodegradable organic pollutants in the water can be removed through the activated sludge;

S502: the bottom of the pool is connected with the bottom of the sludge pool in a diversion process, wherein an activated carbon layer can be set at the intermediate connection part, which can adsorb impurities and bacteria at the connection;

S503: The sludge is lifted to the sludge storage tank by the action of the sludge pump, and the sludge can be temporarily stored in the sludge storage tank. At the same time, the disinfectant can be injected again for disinfection to remove bacteria, and then the impurities and larger dirt can be picked up;

S106: Drainage and effluent treatment, after disinfection treatment, directly discharged.

Preferably, in S102, a plurality of grids formed in series are arranged inside the fine grid channel.

Preferably, in S102, the fine grid adopts an inner inflow orifice grid.

Preferably, in S102, two or more cobblestone layers are laid on the inner bottom of the flocculation reaction tank.

Preferably, in S102, a baffle can also be installed behind the fine grid channel.

Preferably, in S103, the salvage net in S302 is a trumpet-shaped stainless steel net with a hole diameter of five to eight millimeters.

Preferably, in S104, the biological membrane in S401 adopts a multilayer hollow fiber membrane.

Preferably, in S104, the disinfectant in S402 is chlorine.

Preferably, in S105, the sludge pump in S503 adopts a cutting pump with an inner cutting head.

Specific implementation example

This process has been applied in the urban sewage treatment plant of Dingxi City, and the application effect is good.

The designed treatment capacity of Dingxi Urban Sewage Treatment Plant is 10,000 tons/day, and the influent TN concentration is as high as 130mg/l. In order to ensure that the total nitrogen in the effluent reaches the standard, 1.5 tons of methanol and 0.3 tons of phosphorus removal agent are added every day. After the treatment optimization process, the total nitrogen concentration of the biochemical system influent is stable at 80mg/l, the total phosphorus concentration is stable at 6mg/l, the daily dosage of methanol is 1.0 tons, the dosage of phosphorus removal agent is 0.2 tons, and the effluent of the sewage treatment plant is The concentration of total nitrogen and total phosphorus reaches the standard stably, which greatly reduces the cost pressure of sewage treatment plant operation.

The fine grid of the present invention adopts the inner inflow orifice grid, which can effectively remove fine particles such as hair and cotton wool in the sewage, so as to prevent these substances from entering the subsequent system and affecting the operation of the equipment; The turning action can realize the mixing of sewage and chemicals, replacing the traditional mechanical mixing, saving power consumption; adding flocculant and coagulant to the effluent of the grid, forming the fine suspended solids in the water into lumpy sludge, these sludges Through the action of the sludge pump, it is directly transported to the mud storage tank, and then directly dehydrated to form a mud cake for outbound treatment; most of these fine particles in the influent water are particles such as dilute manure flushed out of the septic tank, and nitrogen and phosphorus in the sewage The main source; through this operation, the total amount of nitrogen and phosphorus entering the biochemical system is reduced from the source; in the present invention, there is still some fine garbage due to the sludge precipitated in the primary sedimentation tank, in order to reduce the blocking frequency of the sludge pump, the sludge pump The cutting pump with inner cutting head is selected; this is also a prominent point compared with the conventional sewage treatment pretreatment process, which improves the sewage treatment effect.

Using the technical solutions described in the present invention, or those skilled in the art design similar technical solutions under the inspiration of the technical solutions of the present invention, and achieve the above technical effects, all fall within the protection scope of the present invention.

Claims (10)

1. a kind of pretreatment optimization operation technique for high inflow nitrogen and phosphorus concentration sewage treatment plant, it is characterized in that, this kind of pretreatment optimization operation technique for high inflow nitrogen and phosphorus concentration sewage treatment plant specifically comprises the following steps: Step 1: Prepare water for influent water treatment, discharge domestic sewage and wastewater from sewage treatment plants with high influent nitrogen and phosphorus concentration into the adjustment tank through the municipal pipe network. The domestic sewage contains a large amount of feces, paper scraps, pathogens, and suspended solids. -350mg/L, the organic matter concentration CODCr is between 100-400mg/L, and the suspended organic matter concentration BOD5 is 50-200mg/L; Step 2: The lifting process is carried out by the lifting pump, and the sewage is lifted from the regulating tank to the fine grid channel and the flocculation reaction tank after being acted by the lifting pump. The grille set in the flocculation reaction tank blocks impurities, and at the same time, the blocked impurities are automatically scraped and sent into the grille, and the fine garbage and floating objects are also removed through the fine grille, and regular cleaning work is carried out; Step 3: The sewage enters the flocculation reaction channel process; Step 4: The sewage enters the primary sedimentation tank with the water flow; Step 5: The process of discharging sewage and introducing mud to the mud storage tank; Step 6: Drainage and effluent treatment, after disinfection treatment, direct discharge. 2. as claimed in claim 1, it is characterized in that, in step 3, described sewage enters flocculation reaction channel operation process, and concrete operation steps are as follows: Step 1: Add flocculant to the baffle flocculation channel, and fully stir and mix by stirring rod; The second step: the fine particles in the sewage and the colloidal substances in the water are fully mixed with the agent, and the bonded impurities can be salvaged through the salvage net to take out the floating objects; Step 3: After the flocculation reaction tank is added with a coagulant aid, the small suspended solids in the sewage become larger. In the subsequent flocculation reaction tank, the liquid medicine continues to react, and the suspended particles continue to increase to form large sewage. Mud, ready for subsequent decontamination process. 3. as claimed in claim 1, it is characterized in that, in step 4, described sewage enters primary sedimentation tank with water flow, concretely adopts operation steps as follows : The first step: separation of sewage and sludge, using biofilm to separate the purified water and activated sludge from solid-liquid; biofilm can intercept activated sludge and most of the suspended solids, obtain clear water, and prepare for external use. Row; The second step: the supernatant overflows from the water outlet at the upper part of the primary sedimentation tank and is left to the biochemical treatment system, which is sterilized by the pre-installed disinfectant in the biochemical treatment system, and stirred by the stirring mechanism in the biochemical treatment system to prepare for extraction. Treated clean water. 4. as claimed in claim 1, it is characterized in that, in step 5, described sewage and mud is introduced to the mud storage tank process for the pretreatment optimization operation process of high inflow nitrogen and phosphorus concentration sewage treatment plant, and concretely adopts operation steps as follows : Step 1: Sludge is deposited at the bottom of the pool. At this time, activated carbon carbon balls can be used to adsorb impurities and fine impurity particles in the sludge, and at the same time, activated sludge can be used to remove biodegradable organic pollutants in the water; The second step: the bottom of the pool and the bottom of the sludge pool are connected with the diversion process, in which an activated carbon layer can be set at the middle connection part, which can adsorb impurities and bacteria at the connection; Step 3: The sludge is lifted to the sludge storage tank through the action of the sludge pump, and the sludge can be temporarily stored in the sludge storage tank. At the same time, the disinfectant can be injected again for disinfection to remove bacteria, and then the impurities and larger dirt can be picked up. 5 . The optimized operation process for pretreatment of a sewage treatment plant with high influent nitrogen and phosphorus concentration as claimed in claim 1 , wherein in step 2, a plurality of grids formed in series are arranged inside the fine grid canal. 6 . 6 . The optimized operation process for pretreatment of a sewage treatment plant with high influent nitrogen and phosphorus concentration as claimed in claim 1 , wherein in step 2, the fine grid adopts an inner inflow orifice grid. 7 . 7. the pretreatment optimized operation process for high inflow nitrogen and phosphorus concentration sewage treatment plant as claimed in claim 1, is characterized in that, in step 2, described flocculation reaction tank inner bottom floor is laid with more than two layers of cobblestone Floor. 8 . The optimized operation process for pretreatment of a sewage treatment plant with high influent nitrogen and phosphorus concentration as claimed in claim 1 , wherein in step 2, a baffle can also be installed behind the fine grid canal. 9 . 9. The pretreatment optimized operation process for high influent nitrogen and phosphorus concentration sewage treatment plant as claimed in claim 2, characterized in that, in step 3, in the second step, the salvage net adopts a hole diameter of five millimeters to eight millimeters. mm flared stainless steel mesh. 10. The pretreatment optimized operation process for a high influent nitrogen and phosphorus concentration sewage treatment plant according to claim 4, wherein in step 5, in the third step, the sludge pump adopts cutting with an inner cutting head Pump.

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