CN111410359A

CN111410359A - Pretreatment optimization operation process for high-influent nitrogen and phosphorus concentration sewage treatment plant

Info

Publication number: CN111410359A
Application number: CN201911358429.7A
Authority: CN
Inventors: 杨洛; 黄洁文
Original assignee: Xi'an Water And Animal Husbandry Environment Technology Co ltd
Current assignee: Xi'an Water And Animal Husbandry Environment Technology Co ltd
Priority date: 2019-12-25
Filing date: 2019-12-25
Publication date: 2020-07-14

Abstract

The invention provides a pretreatment optimization operation process for a high-influent nitrogen-phosphorus concentration sewage treatment plant, which belongs to the field of high-influent nitrogen-phosphorus concentration sewage treatment. The fine grid adopts the internal inflow pore plate grid, so that fine particles such as hair and cotton wool in sewage can be effectively removed, and the substances are prevented from entering a subsequent system to influence the operation of equipment; the baffle plate is arranged behind the fine grid channel, and the mixing of sewage and the medicament can be realized through the turning over function of water flow, so that the traditional mechanical mixing is replaced, and the power consumption is saved; in the invention, the sludge deposited in the primary sedimentation tank still has partial fine garbage, and the sludge pump is selected as a cutting pump with an internal cutting head in order to reduce the blocking frequency of the sludge pump.

Description

Pretreatment optimization 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, and particularly relates to a pretreatment optimization operation process for a high-influent nitrogen and phosphorus concentration sewage treatment plant.

Background

The pretreatment optimization operation process is designed for a sewage treatment plant with high influent nitrogen and phosphorus concentration, and aims to reduce the nitrogen and phosphorus content entering a biochemical system from the source through the addition and operation of the process, so that the addition of methanol and a phosphorus removal agent is reduced, and the low-cost and high-efficiency operation of the sewage treatment plant is finally realized.

In the areas with drought and water shortage and industrial shortage in northwest, the water consumption of residents is saved, the drought and rain are reduced, simultaneously, the septic tanks in urban areas are not cleaned as soon as possible, the total nitrogen and total phosphorus concentration of inlet water of the sewage treatment plant can reach 130mg/l (total nitrogen) and 12mg/l (total phosphorus), and is far higher than that of sewage treatment plants in other areas (60-80 mg/l and 5mg/l respectively). In recent years, the environmental protection department increasingly strictly controls the total nitrogen and the total phosphorus of the effluent of a sewage treatment plant, and the sewage treatment plant is forcibly required to be provided with a total nitrogen and total phosphorus on-line instrument to monitor the total nitrogen and the total phosphorus of the effluent all day long.

The influent water of the domestic sewage plant has the characteristics of high nitrogen and phosphorus concentration and low COD concentration. According to the principle of removing the total nitrogen in the sewage, if the effluent reaches the standard stably, a large amount of carbon sources (commonly used methanol) are added into an anoxic zone or a deep bed denitrification filter tank for advanced treatment in a biochemical tank. The total phosphorus removal capacity of a biochemical system is limited, and a large amount of phosphorus removal agent is added to ensure that the total phosphorus of effluent reaches the standard. The adding amount of the methanol and the phosphorus removing agent is in a linear relation with the total nitrogen and total phosphorus concentration of the inlet water, so that great operation cost pressure is brought to a sewage treatment plant with high inlet water nitrogen and phosphorus concentration.

The pretreatment optimization operation process is formed by optimizing the traditional pretreatment process based on the characteristic that nitrogen and phosphorus of inlet water of a sewage treatment plant with high inlet water concentration are mostly fine particles such as organic excrement carried by sewage. By adding and operating the process, the amount of nitrogen and phosphorus entering the biochemical treatment system can be reduced to a certain extent from the source, so that the dosage of methanol and the phosphorus removing agent is finally reduced, and the low-cost and high-efficiency operation of a sewage treatment plant is realized.

However, the existing sewage treatment process has the problems that the treatment is not clean, equipment is easy to block, the resource waste is serious, and the total nitrogen and phosphorus content of a biochemical system after treatment is still large.

Therefore, the invention is very necessary to invent a pretreatment optimization operation process aiming at a sewage treatment plant with high influent nitrogen and phosphorus concentration.

Disclosure of Invention

In order to solve the technical problems, the invention provides a pretreatment optimization operation process for a high-influent nitrogen and phosphorus concentration sewage treatment plant, which aims to solve the problems that the existing sewage treatment process is not clean in treatment and is easy to block equipment, the resource waste is serious and the total nitrogen and phosphorus content of a treated biochemical system is still high, and the pretreatment optimization operation process for the high-influent nitrogen and phosphorus concentration sewage treatment plant specifically comprises the following steps:

preparing water diversion and water inlet treatment, discharging domestic sewage and wastewater of a sewage treatment plant with high influent nitrogen-phosphorus concentration into an adjusting tank through a municipal pipe network, wherein the domestic sewage contains a large amount of excrement, paper scraps, disease protozoa and suspended solid with the concentration of 100-350 mg/L, the concentration of organic matter CODCr is between 100-400 mg/L, and the suspended organic matter concentration BOD5 is 50-200 mg/L;

step two: a lifting process is carried out through a lifting pump, the sewage is lifted into a fine grid channel and a flocculation reaction tank after being acted by the lifting pump from an adjusting tank, and impurities with the size of more than 15mm in the water are removed through the fine grid channel and then enter the flocculation reaction tank; blocking impurities through a grid arranged in the flocculation reaction tank, automatically scraping the blocked impurities and sending the scraped impurities into a grid fence, removing tiny garbage and floating objects through a fine grid, and performing regular cleaning work;

step three: the sewage enters a flocculation reaction channel process, and the specific operation steps are as follows:

the first step is as follows: adding a flocculating agent into the baffle plate flocculation channel, and fully stirring and mixing through a stirring rod;

the second step is that: fine particles in the sewage, colloidal substances in the sewage and the medicament are fully mixed, impurities can be salvaged and bonded through the salvage net, and floating objects are taken out;

the third step: under the action of adding a coagulant aid at the rear end of the flocculation reaction channel, tiny suspended matters in the sewage become large, liquid medicine is continuously reacted in a subsequent flocculation reaction tank, suspended matter particles are continuously increased into particles to form large sludge, and a subsequent decontamination process is prepared;

step four: the sewage enters a primary sedimentation tank along with water flow, and the method specifically comprises the following operation steps:

the first step is as follows: separating sewage and sludge, and performing solid-liquid separation on the purified water and activated sludge by adopting a biological membrane; the biological membrane can intercept activated sludge and most suspended matters to obtain clear water for discharge;

the second step is that: the supernatant overflows from a water outlet at the upper part of the primary sedimentation tank and is retained in a biochemical treatment system, the disinfectant is sterilized by a disinfectant pre-installed in the biochemical treatment system, and the supernatant is stirred by a stirring mechanism in the biochemical treatment system to prepare for leading out treated clear water;

step five: the process of discharging sewage and guiding mud to a mud storage pool specifically comprises the following operation steps:

the first step is as follows: the sludge is deposited at the bottom of the tank, and at the moment, impurities and fine impurity particles in the sludge can be adsorbed by the activated carbon balls, and meanwhile, biodegradable organic pollutants in the water can be removed by the activated sludge;

the second step is that: the tank bottom is communicated with the sludge tank bottom for a diversion process, wherein an activated carbon layer can be arranged at the middle connecting part for adsorbing impurities and bacteria at the connecting part;

the third step: the sludge is lifted to a sludge storage tank under the action of a sludge pump, sludge can be temporarily stored in the sludge storage tank, and meanwhile, disinfectant can be injected again for disinfection, bacteria can be removed, and impurities and larger dirt can be fished;

step six: and (4) treating the discharged water, and directly discharging the water after disinfection treatment.

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

Preferably, in the second step, the fine grid adopts an internal inflow orifice grid.

Preferably, in the second step, more than two goose soft stone layers are laid on the bottom layer in the flocculation reaction tank.

Preferably, in the second step, a baffle plate can be further installed behind the fine grid channel.

Preferably, in the third step, the fishing net in the second step is a trumpet-shaped stainless steel net with a hole diameter of five to eight millimeters.

Preferably, in the fourth step, the biological membrane in the first step is a multilayer hollow fiber membrane.

Preferably, in step four, the disinfectant in the second step employs a chlorine agent.

Preferably, in the fifth step, the sludge pump in the third step adopts a cutting pump with an internal cutting head.

Compared with the prior art, the invention has the following beneficial effects: the pretreatment optimization operation process for the sewage treatment plant with high influent nitrogen and phosphorus concentration is widely applied to the technical field of sewage treatment with high influent nitrogen and phosphorus concentration. The fine grid adopts the internal inflow pore plate grid, so that fine particles such as hair and cotton wool in sewage can be effectively removed, and the substances are prevented from entering a subsequent system to influence the operation of equipment; the baffle plate is arranged behind the fine grid channel, and the mixing of sewage and the medicament can be realized through the turning over function of water flow, so that the traditional mechanical mixing is replaced, and the power consumption is saved; adding a flocculating agent and a coagulant aid into the water discharged from the grille, forming the fine suspended matters in the water into blocky sludge, directly conveying the sludge to a sludge storage tank under the action of a sludge pump, and then directly dehydrating to form a mud cake for outward transportation; most of the fine particles in the inlet water are particles such as thin manure flushed from the septic tank, and the main sources of nitrogen and phosphorus in the sewage; by the operation, the total amount of nitrogen and phosphorus entering a biochemical system is reduced from the source; in the invention, because the sludge precipitated in the primary sedimentation tank still has partial fine garbage, in order to reduce the blocking frequency of a sludge pump, the sludge pump is selected as a cutting pump with an internal cutting head; the method is also a remarkable point compared with the conventional sewage treatment pretreatment process, and the sewage treatment effect is improved.

Drawings

FIG. 1 is a flow chart of a pretreatment optimization operation process of a sewage treatment plant aiming at high influent nitrogen phosphorus concentration.

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

FIG. 3 is a flow chart of sewage entering the primary sedimentation tank along with water flow.

FIG. 4 is a flow chart of the procedure of discharging sewage and guiding mud to a mud storage tank.

Detailed Description

The invention is further described below with reference to the accompanying drawings:

in the figure:

as shown in figure 1

The pretreatment optimized operation process for the sewage treatment plant with high influent nitrogen and phosphorus concentration specifically comprises the following steps:

s101, preparing water diversion and water inlet treatment, discharging domestic sewage and wastewater of a sewage treatment plant with high influent nitrogen-phosphorus concentration into an adjusting tank through a municipal pipe network, wherein the domestic sewage contains a large amount of excrement, paper scraps, disease protozoa and suspended solid with the concentration of 100-350 mg/L, the concentration of CODCr is between 100-400 mg/L, and the suspended organic matter concentration BOD5 is 50-200 mg/L;

s102: a lifting process is carried out through a lifting pump, the sewage is lifted into a fine grid channel and a flocculation reaction tank after being acted by the lifting pump from an adjusting tank, and impurities with the size of more than 15mm in the water are removed through the fine grid channel and then enter the flocculation reaction tank; blocking impurities through a grid arranged in the flocculation reaction tank, automatically scraping the blocked impurities and sending the scraped impurities into a grid fence, removing tiny garbage and floating objects through a fine grid, and performing regular cleaning work;

s103: the sewage enters a flocculation reaction channel process, as shown in the attached figure 2, and the specific operation steps are as follows:

s301: adding a flocculating agent into the baffle plate flocculation channel, and fully stirring and mixing through a stirring rod;

s302: fine particles in the sewage, colloidal substances in the sewage and the medicament are fully mixed, impurities can be salvaged and bonded through the salvage net, and floating objects are taken out;

s303: under the action of adding a coagulant aid at the rear end of the flocculation reaction channel, tiny suspended matters in the sewage become large, liquid medicine is continuously reacted in a subsequent flocculation reaction tank, suspended matter particles are continuously increased into particles to form large sludge, and a subsequent decontamination process is prepared;

s104: sewage enters a primary sedimentation tank along with water flow, and the operation steps are as follows as shown in the attached figure 3:

s401: separating sewage and sludge, and performing solid-liquid separation on the purified water and activated sludge by adopting a biological membrane; the biological membrane can intercept activated sludge and most suspended matters to obtain clear water for discharge;

s402: the supernatant overflows from a water outlet at the upper part of the primary sedimentation tank and is retained in a biochemical treatment system, the disinfectant is sterilized by a disinfectant pre-installed in the biochemical treatment system, and the supernatant is stirred by a stirring mechanism in the biochemical treatment system to prepare for leading out treated clear water;

s105: the process of discharging sewage and guiding mud to a mud storage pool is shown in the attached figure 4, and the operation steps are specifically adopted as follows:

s501: the sludge is deposited at the bottom of the tank, and at the moment, impurities and fine impurity particles in the sludge can be adsorbed by the activated carbon balls, and meanwhile, biodegradable organic pollutants in the water can be removed by the activated sludge;

s502: the tank bottom is communicated with the sludge tank bottom for a diversion process, wherein an activated carbon layer can be arranged at the middle connecting part for adsorbing impurities and bacteria at the connecting part;

s503: the sludge is lifted to a sludge storage tank under the action of a sludge pump, sludge can be temporarily stored in the sludge storage tank, and meanwhile, disinfectant can be injected again for disinfection, bacteria can be removed, and impurities and larger dirt can be fished;

s106: and (4) treating the discharged water, and directly discharging the water after disinfection treatment.

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

Preferably, in S102, the fine grid is an internal flow orifice grid.

Preferably, in S102, more than two goose soft stone layers are laid on the bottom layer in the flocculation reaction tank.

Preferably, in S102, a baffle plate may be further installed after the fine channel.

Preferably, in S103, the fishing 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 is a multilayer hollow fiber membrane.

Preferably, in S104, the disinfectant in S402 employs a chlorine agent.

Preferably, in S105, the sludge pump in S503 is a cutting pump with an internal cutting head.

Detailed description of the preferred embodiment

The process is applied to urban sewage treatment plants in Dengxi cities, and has a good application effect.

The design treatment scale of urban sewage treatment plants in Densey cities is 1.0 ten thousand tons/day, the concentration of TN of inlet water is as high as 130mg/l, in order to ensure that the total nitrogen of outlet water reaches the standard, the adding amount of methanol is 1.5 tons per day, and the phosphorus removing agent is 0.3 ton; after the pretreatment optimization process is added and operated, the total nitrogen concentration of inlet water of a biochemical system is stabilized at 80mg/l, the total phosphorus concentration is stabilized at 6mg/l, the adding amount of methanol is 1.0 ton per day, the adding amount of a phosphorus removing agent is 0.2 ton, the total nitrogen concentration of outlet water of a sewage treatment plant stably reaches the standard, and the operation cost pressure of the sewage treatment plant is greatly reduced.

The fine grid adopts the internal inflow pore plate grid, so that fine particles such as hair and cotton wool in sewage can be effectively removed, and the substances are prevented from entering a subsequent system to influence the operation of equipment; the baffle plate is arranged behind the fine grid channel, and the mixing of sewage and the medicament can be realized through the turning over function of water flow, so that the traditional mechanical mixing is replaced, and the power consumption is saved; adding a flocculating agent and a coagulant aid into the water discharged from the grille, forming the fine suspended matters in the water into blocky sludge, directly conveying the sludge to a sludge storage tank under the action of a sludge pump, and then directly dehydrating to form a mud cake for outward transportation; most of the fine particles in the inlet water are particles such as thin manure flushed from the septic tank, and the main sources of nitrogen and phosphorus in the sewage; by the operation, the total amount of nitrogen and phosphorus entering a biochemical system is reduced from the source; in the invention, because the sludge precipitated in the primary sedimentation tank still has partial fine garbage, in order to reduce the blocking frequency of a sludge pump, the sludge pump is selected as a cutting pump with an internal cutting head; the method is also a remarkable point compared with the conventional sewage treatment pretreatment process, and the sewage treatment effect is improved.

The technical solutions of the present invention or similar technical solutions designed by those skilled in the art based on the teachings of the technical solutions of the present invention are all within the scope of the present invention.

Claims

1. The pretreatment optimization operation process for the high-influent nitrogen and phosphorus concentration sewage treatment plant is characterized by comprising the following steps:

step three: the sewage enters a flocculation reaction channel process;

step four: sewage enters a primary sedimentation tank along with water flow;

step five: discharging sewage and guiding mud to a mud storage pool;

2. The pretreatment optimizing operation process for the sewage treatment plant with high influent nitrogen phosphorus concentration according to claim 1, wherein in the third step, the sewage enters a flocculation reaction channel process, and the specific operation steps are as follows:

the third step: under the action of adding the coagulant aid at the rear end of the flocculation reaction channel, tiny suspended matters of the sewage become large, liquid medicine is continuously reacted in a subsequent flocculation reaction tank, suspended matter particles are continuously increased by the particles to form large sludge, and a subsequent decontamination process is prepared.

3. The pretreatment optimized operation process for the high influent nitrogen phosphorus concentration sewage treatment plant according to claim 1, wherein in the fourth step, the sewage enters the primary sedimentation tank along with the water flow, and the operation steps are specifically as follows:

the second step is that: and the supernatant overflows from a water outlet at the upper part of the primary sedimentation tank and is retained in the biochemical treatment system, the disinfectant is sterilized by the disinfectant pre-installed in the biochemical treatment system, and the supernatant is stirred by a stirring mechanism in the biochemical treatment system to prepare for leading out the treated clear water.

4. The pretreatment optimized operation process for the high influent nitrogen phosphorus concentration sewage treatment plant according to claim 1, wherein in the fifth step, the operation steps of sludge discharge and sludge introduction to the sludge storage tank are specifically adopted as follows:

the third step: promote to storing up the mud pond through the effect of sludge pump, can keep in mud through storing up the mud pond, can pour into disinfectant into again simultaneously and disinfect, get rid of the bacterium, salvage impurity and great filth again.

5. The pretreatment optimized operation process aiming at the sewage treatment plant with high influent nitrogen phosphorus concentration as claimed in claim 1, wherein in the second step, a plurality of grids formed in series are arranged in the fine grid channel.

6. The pretreatment optimized operation process for the sewage treatment plant with high influent nitrogen phosphorus concentration as claimed in claim 1, wherein in the second step, the fine grid adopts an internal influent orifice plate grid.

7. The pretreatment optimized operation process aiming at the sewage treatment plant with high influent nitrogen phosphorus concentration as claimed in claim 1, wherein in the second step, more than two goose soft stone layers are laid on the bottom layer in the flocculation reaction tank.

8. The pretreatment optimized operation process for the sewage treatment plant with high influent nitrogen phosphorus concentration as claimed in claim 1, wherein in the second step, a baffle plate can be further installed behind the fine grid channel.

9. The pretreatment optimized operation process for the high influent nitrogen phosphorus concentration sewage treatment plant according to claim 2, wherein in the third step, the fishing net in the second step is a trumpet-shaped stainless steel net with a hole diameter of five to eight millimeters.

10. The pretreatment optimized operation process aiming at the sewage treatment plant with high influent nitrogen phosphorus concentration in the claim 4, wherein in the fifth step, the sludge pump in the third step adopts a cutting pump with an internal cutting head.