CN104891655B - Device and method for treating high ammonia nitrogen wastewater - Google Patents

Abstract

The invention discloses a device and a method for treating high ammonia nitrogen wastewater. The method comprises the following steps: inoculating active sludge to a reactor, starting a stirrer, and circulating the following steps: 1) starting an aeration system and a water feed pump, feeding water in a sequencing batch, delivering the high ammonia nitrogen wastewater to the reactor according to the designed treatment quantity, and closing the water feed pump; 2) closing the aeration system, under the action of a carbon source, reducing nitrate nitrogen in the wastewater into nitrite nitrogen, and reducing the nitrite nitrogen into nitrogen; 3) starting the aeration system, to oxidize ammonia nitrogen and organic matters in the wastewater, wherein the ammonia nitrogen is oxidized into nitrite nitrogen, and the nitrite nitrogen is oxidized into nitrate nitrogen; and 4) after 60-120min at the beginning of an aerobic stage, starting a water discharge pump, filtering the wastewater of the designed treatment quantity by a membrane in a membrane assembly, then discharging the filtered wastewater, and sequentially closing the water discharge pump and the aeration system. By combining the high sludge concentration SBR (sequencing batch reactor) process with the membrane separation technology, the device and the method have the operating characteristics of sequencing batch water feed and continuous water discharge; and the adding quantity of the carbon source is more accurate.

Description

Device and method for treating high ammonia nitrogen wastewater

technical field

The invention relates to a device and a method for treating high-ammonia-nitrogen wastewater, in particular to a device and a method for treating high-ammonia-nitrogen wastewater by using an SBR process and membrane separation technology, and belongs to the field of sewage treatment.

Background technique

With the gradual improvement of human requirements on the environment, the sewage discharge standards will continue to be tightened. Biological nitrification and denitrification is currently the most commonly used sewage denitrification method. The traditional biological method usually adopts the whole nitrification-denitrification process to remove nitrogen, that is, the aerobic unit uses ammonia oxidizing bacteria (Ammonia Oxidizing Bacteria, AOB) to oxidize ammonia nitrogen into nitrite nitrogen, and then the nitrifying bacteria (Nitrite Oxidizing Bacteria, NOB) Nitrate nitrogen is oxidized to nitrate nitrogen; the facultative oxygen (anaerobic) unit reduces the generated nitrate nitrogen to nitrite nitrogen and then reduces it to nitrogen. In actual operation, especially in the process of treating wastewater with high ammonia nitrogen and low carbon-to-nitrogen ratio, the supplement of external carbon sources required for the oxidation of ammonia nitrogen to nitrate nitrogen in the aerobic section and the reduction of nitrate nitrogen to nitrogen in the facultative section will be different. Incurring excessive operating costs. Therefore, it is imminent to research and develop a new denitrification process that optimizes energy consumption. In 1989, Yamamoto K et al. published the first research on submerged MBR. Compared with the external MBR, the submerged MBR has the advantages of reduced energy consumption and compact footprint due to the omission of the circulating pump, and has gradually been favored in research and engineering applications. Pay attention to (YamamotoK, HiasaH, TalatM, et al.1989. Direct solid liquid separation using holllowfibe membranes inactivated sludge aeration tanks). In 1998, Hellinga C et al. used ammonia oxidizing bacteria whose generation time was shorter than that of nitrifying bacteria to select an appropriate sludge residence time ( SRT) eliminates nitrifying bacteria and retains ammonia oxidizing bacteria, thereby realizing the first nitrification-denitrification process in a single reactor, that is, ammonia nitrogen is oxidized to nitrite nitrogen and then directly reduced to nitrogen (Hellinga C, Schellen AAJC, Mulder JW, van LoosdrechtMCM, Heijen, JJ, 1998. The SHARON Process: an innovative method for nitrogen removal from ammonium-rich wastewater. Water Sci. Technol. 37, 135-142). Compared with the whole process of nitrification-denitrification, this process can save up to 25% of aeration, 40% of external carbon sources, and reduce 40% of biological increment. This has led to subsequent research work in the world aimed at broadening the application range of nitrosation-denitritation or reducing its requirements for operating conditions, and seeking the optimal combination of traditional processes and MBR. Peng Yongzhen and others invented the device and method for deep denitrification of low C/N domestic sewage by anoxic/aerobic SBR + anammox + aerobic SBR process; Fan Yaobo and others invented the integrated A2/O-MBR reactor. In addition, the automatic control system is also gradually applied to the sewage treatment process to facilitate management and save manpower.

In the above research, although SBR can achieve a good denitrification effect, it requires a higher sludge concentration (above 10,000mg/L) for high ammonia nitrogen wastewater, which results in a longer sedimentation time for the effluent and increases the HRT of the process. At the same time, due to the high Under the sludge concentration, the SS of the effluent is high, which directly leads to the instability of the effluent quality. Therefore, it is imminent to develop devices and methods for treating high-ammonia-nitrogen wastewater using sequencing batch activated sludge process and membrane separation technology.

Contents of the invention

The purpose of the present invention is to provide a device and method for treating high-ammonia-nitrogen wastewater. The device optimizes the membrane technology with high retention efficiency and the SBR process, shortens the hydraulic retention time (HRT) of the process while realizing good effluent quality, and has the advantages of Sequential batch water inlet and continuous water outlet operation characteristics; at the same time, the present invention uses pH probes, DO (dissolved oxygen) probes and ORP (oxidation-reduction electrode potential) probes to continuously monitor the reactor and establish an automatic control system, which can control carbon dioxide in time. source, transforming the nitrification-denitrification process into a short-cut nitrification-denitrification process.

The invention provides a device for treating high-ammonia-nitrogen wastewater, which includes a water inlet system, an aeration system, a carbon source dosing system, a reaction system, a membrane separation system and a water outlet system;

The reaction system includes a reactor, the reactor is a container, and an agitator is arranged above the reactor;

The water inlet system includes a raw water tank, and the raw water tank is connected to the reactor through a water inlet pump;

The aeration system includes an air compressor, a gas flow meter and an aerator, and the aerator is placed in the reactor;

The carbon source dosing system includes a carbon source storage tank, and the carbon source storage tank is connected to the reactor through a carbon source dosing pump;

The membrane separation system is a membrane module, and the membrane module is placed in the reactor;

The water outlet system includes a water production tank, and the water outlet of the membrane module is connected with the water production tank through a water outlet pump.

During the operation of the device of the present invention, at first, the activated sludge is inoculated into the reactor; the high ammonia nitrogen wastewater is stored in the raw water tank, and under the action of the water inlet pump, the high ammonia nitrogen wastewater is transported into the reactor; when the aeration system is closed, under the action of the carbon source added by the carbon source dosing system, the nitrite nitrogen in the high ammonia nitrogen wastewater is reduced to nitrate Nitrogen, nitrate nitrogen is reduced to nitrogen (facultative oxygen stage or anaerobic stage); When the aeration system is in the open state, the aeration system can provide oxygen to the wastewater in the reactor, The ammonia nitrogen in the sludge is oxidized to nitrite nitrogen under the action of ammonia oxidizing bacteria in the sludge, and the nitrite nitrogen is oxidized to nitrate nitrogen under the action of nitrite oxidizing bacteria (aerobic stage); the treated After passing through the membrane separation system, the waste water is further purified, and is discharged into the produced water tank through the water outlet pump.

In the above device, the device also includes a real-time control system, the implementation control system includes a probe, an integrated circuit box and a digital touch panel; the probe includes a pH probe, an ORP probe and a dissolved oxygen DO probe, all of which are connected to the The integrated circuit box is connected, and the integrated circuit box is connected with the digital touch panel to the real-time control system; the pH probe, the ORP probe and the pH probe are recorded and calculated by the integrated circuit box and the digital touch panel The real-time monitoring data of the dissolved oxygen DO probe can control the start and stop of the water inlet and outlet pumps, carbon source dosing pumps, aeration system and agitator according to the set program, and control the alternate operation of each reaction unit in real time.

In the above device, the aerator can be placed at the bottom of the reactor for sufficient aeration.

In the above device, the membrane module can be placed on the side wall of the reactor to avoid hindering the operation of the agitator above the reactor and avoid damage to the reactor and the agitator;

The membrane module is a plate-and-frame membrane module, and the plate-and-frame membrane module includes 1 to 2 membrane units, each of which is composed of two membranes; the material of the membrane is polyvinylidene fluoride, and the pore diameter is ≤0.1μm, the effective area of each membrane unit (membrane element) is 0.5m ² ; the inside of the membrane module is also equipped with an aerator, which is connected with another air compressor and another gas flow meter in turn, for The aeration of the membrane reduces the pollution of the membrane and prolongs the service life of the membrane.

The present invention further provides a method for processing high ammonia nitrogen wastewater, comprising the steps of:

Inoculate the activated sludge into the reactor, open the agitator, and repeat the following steps (1)-step (4):

(1) Water intake stage: open the aeration system and the water intake pump, adopt sequential batch type water intake, according to the designed treatment capacity, the high ammonia nitrogen wastewater to be treated is input into the reactor, close the inlet pump;

(2) Facultative oxygen phase: close the aeration system, under the action of carbon source, the nitrate nitrogen in the wastewater is reduced to nitrite nitrogen, and the nitrite nitrogen is reduced to nitrogen;

(3) Aerobic stage: the aeration system is turned on, the ammoniacal nitrogen and organic matter in the wastewater are oxidized, the ammoniacal nitrogen is oxidized to nitrite nitrogen, and the nitrite nitrogen is oxidized to nitrate nitrogen;

(4) Drainage stage: after the aerobic stage starts for 60 to 120 minutes, the outlet pump is turned on, the waste water with a designed treatment capacity is discharged after being filtered by the membrane in the membrane module, and the outlet pump and The aeration system.

In the above method, the method also includes the step of starting the real-time control system throughout the whole process to monitor the redox electrode potential, pH value and dissolved oxygen in the high ammonia nitrogen wastewater;

The aerator in the membrane module is fully opened, and the aeration flow rate can be 5-15L/min. Specifically, two aeration membranes can be installed, and the aeration flow rate is 8L/min, so as to reduce membrane pollution and prolong the service life of the membrane .

In the above-mentioned method, the concentration of the activated sludge of described inoculation can be 5000mg/L～5500mg/L, 5000mg/L or 5500mg/L, specifically can come from the return sludge of urban sewage treatment plant; Due to the high ammonia nitrogen wastewater of the present invention The treatment needs to be carried out under high sludge concentration. Gradiently increasing the influent concentration of sewage can increase the concentration of activated sludge to 10000mg/L～12000mg/L, specifically to 11000mg/L;

The gradient increase is divided into three stages. The first stage can be 5-10 days, specifically 5-7 days, 5 days or 7 days, and the influent is diluted to 1/4 of the concentration of the original sewage; the second stage The first stage can be 5-10 days, specifically 5-7 days, 5 days or 7 days, and the influent is diluted to 1/2 of the original sewage concentration; the third stage can be 30-55 days, specifically 45 days days until the start-up phase is completed;

When the removal rate of ammoniacal nitrogen (influent ammonia nitrogen concentration/effluent ammonia nitrogen concentration) in the high ammonia nitrogen wastewater is greater than 80%, and the nitrate nitrogen in the discharged wastewater accounts for greater than 70% of the total nitrogen content in the wastewater, the reaction The reactor achieves stable denitrification throughout the whole process, the start-up phase is completed, and the gradient increase can make the microorganisms in the sludge adapt to the water quality of the raw sewage and the environmental conditions of the reactor as soon as possible.

In the above method, in step (1), the concentration of ammoniacal nitrogen in the high-ammonia-nitrogen wastewater can be 400-900 mg/L, and the COD content can be 2000-6000 mg/L;

The high ammonia nitrogen wastewater comes from livestock and poultry breeding wastewater, landfill leachate or sludge digestate;

The designed throughput can be 0.5-1.5L/cycle, specifically 1-1.5L/cycle, 1L/cycle or 1.5L/cycle;

The input flow rate may be 0.5-1L/min, specifically 0.5L/min;

The high-ammonia-nitrogen wastewater to be treated is input into the reactor for 3-5 minutes, specifically 5 minutes, and after being uniformly mixed with the high-concentration activated sludge mixture in the reactor, it enters the subsequent facultative stage.

In the above method, in step (2), the organic matter in the high ammonia nitrogen wastewater can be preferentially used as a carbon source to provide electrons for the reduction of the nitrate nitrogen and the nitrite nitrogen in the facultative oxygen stage, when the When the carbon source in the wastewater is insufficient, the carbon source dosing pump is turned on in time to add carbon source to the reactor. In this way, the dosage of carbon source can be made more accurate, saving carbon source and reducing cost .

When the change value of the redox electrode potential of the wastewater over time, that is, dORP/dt, is 0 to -5, it is determined that the carbon source is insufficient, and the carbon source dosing pump is turned on to add a carbon source to the reactor. The time can be 0.5-1min, specifically 0.5min or 1min, and after 10-20min, specifically 10-15min, 10min or 15min, enter the next judgment; when the dORP/dt is less than -5, you can After a delay of 10 to 30 minutes, specifically 20 to 30 minutes, 20 to 25 minutes, 25 to 30 minutes, 20 minutes, 25 minutes or 30 minutes, the aeration system is turned on, and the denitrification can be ensured through the delay fully carried out.

In the above method, in step (3), the time of the aerobic stage can be 9 to 180 minutes, specifically 120 to 150 minutes, 120 to 135 minutes, 135 minutes or 150 minutes, and the aeration flow rate can be 0.5 to 10 L/min, specifically It can be 4~5L/min, 4L/min or 5L/min;

In the above method, in step (4), the time of the drainage stage can be 30-90 minutes, specifically 40-60 minutes, 40 minutes or 60 minutes, and the water outlet pump is intermittent suction, which can be turned on every 8-10 minutes Stop for 2 to 4 minutes, specifically, stop for 2 minutes every 8 minutes.

In the above method, the temperature of the reactor may be 20-30°C, specifically 20-25°C, 20°C or 25°C.

In the above method, in order to convert the whole process of nitrification-denitrification into short-range nitrification-denitrification, it is necessary to promote the growth of ammonia oxidizing bacteria (AOB) and inhibit the growth of nitrite oxidizing bacteria (NOB), using at least one of the following 1)-3) This method converts the whole process of nitrification-denitrification into short-range nitrification-denitrification:

1) Optimizing the aeration time method: after denitrification is stable, in the aerobic stage of each cycle, when the pH value in the wastewater does not change over time, that is, when dpH/dt=0, close the aeration system;

2) Free ammonia controlled accumulation method: After denitrification is stable, in the aerobic stage, reduce the aeration flow rate of the aeration system, and when the concentration of free ammonia in the wastewater rises to 20 mg/L or more, restore Aeration flow;

The aeration flow rate in the entire cycle of the aeration system can be reduced to 0.2-1L/min, specifically to 0.5L/min;

In the above method 1), in the aerobic unit of each cycle, the duration of the aerobic unit is controlled in real time according to the "ammonia valley" (ammonia valley) on the pH continuous monitoring curve, that is, the appropriate aeration flow rate is first used to continuously aerate, Stop aeration immediately when the "ammonia valley point" appears on the pH continuous monitoring curve. By optimizing the aeration time to gradually reduce the oxidation of nitrous nitrogen, the denitrification process gradually changes from full nitrification-denitrification to short-range nitrification and denitrification, and the nitrification rate can continue to increase and finally reach 80%.

In the above method 2), by reducing the aeration flow rate and controlling the low dissolved oxygen (DO), the free ammonia concentration (FA) in the reaction system is increased to greater than or equal to 20 mg/L, and the growth rate of ammonia oxidizing bacteria is greater than that of nitrous acid. Oxidizing bacteria. Then restore the aeration flow rate to the appropriate aeration flow rate and continue aeration until the nitrification rate reaches more than 80%, and then resume the normal inflow and outflow water treatment cycle to realize the nitrification-denitrification of ammonia nitrogen wastewater treatment.

The stable denitrification described in the above 1) and 2) all refers to when the removal rate of ammoniacal nitrogen in the waste water is greater than 80%, and the content of nitrate nitrogen in the discharged waste water accounts for more than 80% of the total nitrogen in the waste water. 70% of the time;

3) SRT control method: the method also includes the step of sludge discharge, and after the aerobic stage, the average residence time of the sludge in the reactor is controlled to be 12-15 days.

In the above method 3), since the sludge age of ammonia oxidizing bacteria is generally 10 to 12 days, and the sludge age of nitrous acid oxidizing bacteria is generally 18 to 20 days, the average residence time of sludge in the control system is 12 to 15 days. The number is gradually reduced, so that the proportion of ammonia oxidizing bacteria in the real nitrifying bacteria group continues to increase, and the nitrification rate can continue to increase.

Utilizing the device and method of the present invention can realize the nitrosation-denitritation approach to process high ammonia nitrogen wastewater (nitrosation rate reaches 80%), and ensure that the reactor efficiently removes nitrogen (about 95% TN, about 99% NH ₃ -N and about 98 %COD), the water production rate is 2-6 (L/h), which reduces the hydraulic retention time, reduces aeration energy consumption, and saves external carbon sources.

The device and method for treating high-ammonia-nitrogen wastewater of the present invention have the following advantages:

1) The present invention combines the high sludge concentration SBR process with membrane separation technology, has the operation characteristics of sequential batch water inflow and continuous water discharge, and realizes the optimization of anoxic/aerobic SBR sequence batch reaction and continuous operation of membrane separation technology Combine;

2) The present invention adopts the method of membrane effluent, which ensures the effluent water quality under higher sludge concentration, simplifies the process of traditional SBR, and shortens the HRT;

3) The present invention uses the change value of ORP per unit time as the basis for judging the denitrosation process, controls the carbon source dosing pump to perform pulsed dosing, improves the accuracy of carbon source dosing, saves the amount of external carbon source dosing and reduces sewage treatment costs;

4) Use the pH probe to monitor the process of ammonia oxidation reaction online, determine the maximum accumulation time of NO ₂ , optimize the aeration time to save aeration and reduce the cost of sewage treatment.

In a word, the present invention combines high sludge concentration SBR process with membrane separation technology, and uses pH, DO (dissolved oxygen) and ORP (oxidation-reduction potential) electrodes to continuously monitor the reactor to establish an automatic control system, which is a new SBR+ MBR semi-continuous operation process.

Description of drawings

Fig. 1 is a structural schematic diagram of the device for treating high-ammonia-nitrogen wastewater according to the present invention.

Fig. 2 is a schematic diagram of optimizing the aeration time at the "ammonia valley point" on the real-time pH curve at around 25°C in Example 3 to realize nitrosation-denitritation.

Fig. 3 is the operation logic diagram of treating high ammonia nitrogen wastewater in embodiment 3.

The marks in the figure are as follows:

1.1 Raw water tank, 1.2 Inlet pump, 2.1 First air compressor, 2.2 First gas flow meter, 2.3 Aeration pan, 3.0 Anoxic/aerobic SBR reactor, 3.1 Agitator, 3.2 Sampling valve, 3.3 Mud discharge valve, 3.4 carbon tube, 3.5 water inlet pipe, 4.1 flat membrane, 4.2 plexiglass membrane shell, 4.3 water outlet, 4.4 microporous tube aerator, 4.5 second air compressor, 4.6 second gas flow meter, 4.7 peristaltic pump, 4.8 Pressure gauge, 4.9 Produced water tank, 5.1 Carbon source storage tank, 5.2 Carbon source dosing pump, 6.1 pH probe, 6.2 ORP probe, 6.3 Dissolved oxygen DO probe, 6.4 Integrated circuit box, 6.5 Digital touch panel.

detailed description

The experimental methods used in the following examples are conventional methods unless otherwise specified.

The materials and reagents used in the following examples can be obtained from commercial sources unless otherwise specified.

In the following examples, when gray water, sludge anaerobic digestion liquid, and landfill leachate are treated, the denitrification carbon source used is industrial methanol. In the treatment of livestock and poultry wastewater, Manure Slurry is used as the denitrification carbon source in order to save operating costs. The preparation method of the thick slurry of livestock and poultry manure is as follows: the pig manure is ground and sieved (10 meshes) and diluted with water to form a thick slurry with a COD content of 50,000-100,000 mg/L.

In the following examples, the aeration flow required in the reactor is calculated by the following empirical formula:

Q=q×MLSS×In (Formula 1)

Among them, Q—appropriate aeration flow rate, the unit is L/min;

MLSS (Mixed Liquid Suspended Solids Concentration)—used to indicate the concentration of activated sludge in mg/L;

In—influent NH ₃ -N concentration, unit is mg/L;

q—empirical calculation constant, which comes from experiments. For the appropriate aeration flow rate, its value is 200-400.

In the following examples, the aeration flow required by the membrane in the flat membrane module is calculated by the following formula:

The aeration volume required by the membrane element = n × q (Formula 2)

Among them, n—the number of membrane elements (pieces);

q—the gas volume required for a single film (L/min), which comes from experiments. For the appropriate aeration flow rate, its value is 5-15.

Chemical oxygen demand (COD), phosphorus content (TP), total organic carbon (TOC), biochemical oxygen demand (BOD ₅ ), ammoniacal nitrogen (NH ₃ -N) content, The content of nitrite nitrogen (NO ₂ -N) and nitrate nitrogen (NO ₃ -N) can be detected by the methods and instruments in Table 1 below:

Table 1 Measuring indicators and research methods

The present invention will be further described through specific embodiments below in conjunction with the accompanying drawings, but the present invention is not limited to the following embodiments.

Embodiment 1, the device for processing high ammonia nitrogen wastewater

As shown in Figure 1, the present invention provides a device for treating high-ammonia-nitrogen wastewater using sequencing batch activated sludge process and membrane separation technology, which includes water inlet system, aeration system I, reaction system, membrane separation system, water outlet system, carbon source dosing system and implementation control system;

The reaction system includes a reactor (3.0), which is an open container, an agitator (3.1) is arranged above the open container, and a sampling valve (3.2), a sludge discharge valve (3.3), and an agitator (3.1) are respectively arranged on the side wall Carbon pipe (3.4) and water inlet pipe (3.5);

The water inlet system includes a raw water tank (1.1), which is connected with the water inlet pipe (3.5) of the anoxic/aerobic SBR reactor (3.0) through the water inlet pump (1.2);

The aeration system I includes a first air compressor (2.1), a first gas flow meter (2.2) and an aeration tray (2.3) placed at the bottom of the anoxic/aerobic SBR reactor (3.0);

The membrane separation system is a plate and frame membrane module placed on the side wall of the anoxic/aerobic SBR reactor (3.0), which consists of 1 to 2 flat membrane membrane units (4.1) and an external plexiglass shell (4.2 ), its upper and lower sides are connected with the external sewage, and each flat membrane membrane unit (4.1) is fixed on the membrane frame by a flat membrane (material: polyvinylidene fluoride PVDF, effective membrane area: 0.25m ² , membrane pore size ≤ 0.1μm) Obtained above, each membrane frame is provided with a sub-water outlet, the top of the whole plate-and-frame membrane module is provided with a water outlet (4.3) connected with each sub-water outlet, and the bottom of the plexiglass casing (4.2) is provided with a microporous tube Type aerator (4.4), connected with the second air compressor (4.5) and the second gas flow meter (4.6), constitutes the aeration system II, which flushes the membrane in the plate-and-frame membrane module to avoid pollution; The system includes a produced water tank (4.9), which is connected to the water outlet (4.3) of the plate-and-frame membrane module through a peristaltic pump (4.7) for suction and drainage (the mixed solution seeps through the flat membrane surface), and is monitored by a pressure gauge (4.8). Transmembrane pressure difference, the sewage separated by the membrane is pumped into the produced water tank;

The carbon source dosing system includes a carbon source storage tank (5.1), which is connected to the carbon adding pipe (3.4) of the anoxic/aerobic SBR reactor (3.0) through the carbon source dosing pump (5.2);

The real-time control system includes a pH probe (6.1), an ORP probe (6.2) and a dissolved oxygen DO probe (6.3). The three probes are inserted into the wastewater in the reactor when in use, and are respectively connected with the integrated circuit box (6.4), integrated The circuit box (6.4) is connected with the digital touch panel (6.5), and controls the start and stop of the water inlet and outlet pumps, that is, the water inlet pump and the peristaltic pump, the carbon source dosing pump, the aeration system and the agitator according to the set program, so as to control each water flow in real time. Alternate reaction units.

Embodiment 2, utilizing sequencing batch type activated sludge process and membrane separation technology to treat aquaculture wastewater

The device in Example 1 is used to treat a certain intensive aquaculture wastewater, and the temperature of the control reactor is 25±0.5°C. The treatment process includes the following steps:

Inoculate the return sludge of urban sewage treatment plant with a concentration of 5500mg/L into the reactor, turn on the agitator, aeration system I (aeration flow rate is 5L/min), aeration system II (aeration flow rate is 8L/min , the aeration rate for the entire membrane flushing is set according to two membranes), the water inlet pump and the implementation control system adopt the method of gradient water (sewage) inflow, so that the sludge concentration gradually increases to 11000mg/L, and the gradient water inflow control is as follows : The first stage is 7 days, the influent is diluted to 1/4 of the original sewage concentration, the second stage is 7 days, the influent is diluted to 1/2 of the original sewage concentration, the third stage begins, the influent Using raw sewage, when the removal rate of ammonia nitrogen in the sewage (influent ammonia nitrogen concentration/outlet ammonia nitrogen concentration) is greater than 80%, and when the nitrate nitrogen in the discharged waste water accounts for more than 70% of the total nitrogen content in the waste water, the reaction The denitrification device reaches a stable whole process (the third stage is 45 days in total), the start-up stage is completed, turn off the water inlet pump and aeration system I, repeat the following steps (1)-step (4) until all waste water is discharged, and turn off the agitator , Aeration system Ⅱ and implementation control system:

(1) Water intake stage: Turn on the water intake pump and aeration system I, adopt sequential batch water intake, and according to the designed treatment capacity (1.5L/cycle), the aquaculture wastewater to be treated is quickly input into the reactor (the input flow rate is 0.5 L/min), turn off the water inlet pump and keep it for 5min.

(2) Facultative oxygen stage: close the aeration system I, under the action of carbon source, the nitrate nitrogen in the wastewater is reduced to nitrite nitrogen, and the nitrite nitrogen is reduced to nitrogen. When dORP/dt is greater than -5, it is determined that the carbon source in the wastewater is insufficient for complete denitrification, and the carbon source dosing pump is turned on in time to add carbon source to the reactor in a pulsed manner. The time for each start is 0.5min. After keeping it for 10 minutes, continue to use the value of dORP/dt as the basis for judgment, and so on, until an appropriate amount of external carbon source is added to ensure complete denitrification, that is, when the value of dORP/dt is less than -5, it is determined that the carbon source is sufficient, and the extension is extended for 20 minutes. Denitrification proceeded smoothly.

(3) Aerobic stage: Turn on the aeration system I, NH ₃ -N and COD in the aquaculture wastewater are oxidized to NO ₂ -N, and NO ₂ -N is oxidized to NO ₃ -N.

(4) Drainage stage: 80 minutes after the above-mentioned aerobic stage, start the peristaltic pump to suction and drain water. The operation mode of the peristaltic pump is to stop for 2 minutes every 8 minutes, and the designed processing capacity (1.5L/cycle) is processed by step (2). The sewage is discharged through the percolation of the flat membrane in the plate and frame membrane module, and the drainage is completed before the end of the aerobic process, and the peristaltic pump and aeration system I are turned off.

In this embodiment, the time of each cycle is about 170 minutes, the average time of the aerobic stage is 120 minutes, the total drainage time of each round is 40 minutes, and the pumped water output is about 3 L/h.

In this embodiment, the whole nitrification-denitrification process is controlled as a short-range nitrification-denitrification process by the following two methods:

(1) Free ammonia controlled accumulation method:

In the first 20 days after the stable operation of the reactor, the effluent NH ₃ -N and NO ₂ -N were maintained at a low concentration level, while NO ₃ -N accounted for more than 80% of the total nitrogen (TN), and the removal rate of NH ₃ -N was at more than 90 percent. From the 20th day to the 32nd day, the aeration flow was reduced from 5.0L/min to 0.5L/min, the NH ₃ -N in the system increased gradually, while the NO ₃ -N decreased rapidly. When the free ammonia concentration in the system rises to about 36.3mg/L (NH ₃ -N≈205mg/L; pH=8.8), immediately restore the aeration rate to 3.0L/min for continuous aeration. NH ₃ -N decreased to less than 5 mg/L in the next 6 days. During this process, NO ₂ -N accumulated significantly in the system, up to about 160mg/L, while NO ₃ -N only increased to 30mg/L. This shows that after controlling the increase of FA (free ammonia), the oxidation performance of the reactor to nitrous nitrogen is obviously inhibited. Afterwards, through real-time control and supplementation of corresponding carbon sources, NO ₂ -N and NO ₃ -N in the effluent decreased, but the concentration of NO ₂ -N (average 38 mg/L) was still significantly higher than that of NO ₃ -N (average 9 mg/L ). The nitrosation rate of the continuous long-term operation of the reactor reaches up to 85%.

(2) SRT control method:

In the present embodiment, the average residence time of the control system sludge is 15 days, because the sludge age of the ammonia oxidizing bacteria is generally 10-12 days under the control conditions of the present embodiment (T=25°C, pH≥7.0), while the nitrous acid The sludge age of oxidizing bacteria is generally 18-20 days, which can gradually reduce the number of nitrite oxidizing bacteria, so that the proportion of ammonia oxidizing bacteria in the real nitrifying bacteria group continues to increase, and the nitrification rate can continue to increase.

See Table 1 for the concentration and removal rate of pollutants in the aquaculture wastewater before and after the above steps of treatment.

Concentration and removal rate of pollutants in and out of water in table 1 embodiment 1

ND: not detected

Embodiment 3, utilizing sequencing batch type activated sludge process and membrane separation technology to treat landfill leachate

The device in Example 1 is used to process the landfill leachate, and the temperature of the control reactor is 25 ± 0.5 ° C. The treatment process includes the following steps:

Inoculate the return sludge of urban sewage treatment plant with a concentration of 5500mg/L into the reactor, turn on the agitator, aeration system I (aeration flow rate is 4L/min), aeration system II (aeration flow rate is 8L/min ), the water inlet pump and the implementation control system adopt the method of gradient water inlet (sewage) to gradually increase the sludge concentration to 11000mg/L, and the gradient water inlet control is as follows: the first stage is 5 days, and the inlet water is diluted to the original 1/4 of the sewage concentration, the second stage is 5 days, the influent is diluted to 1/2 of the original sewage concentration, the third stage begins, the influent uses the original sewage, and the start-up is completed after 15 days. When the removal rate of ammoniacal nitrogen in the sewage (influent ammonia nitrogen concentration/effluent ammonia nitrogen concentration) is greater than 80%, and the content of nitrate nitrogen in the discharged wastewater accounts for more than 70% of the total nitrogen in the wastewater, the reactor reaches a stable whole process Denitrification, the start-up phase is completed, turn off the water inlet pump and aeration system I, repeat the following steps (1)-step (4) until all waste water is discharged, turn off the agitator, aeration system II and the implementation control system, and run the logic diagram As shown in Figure 3:

(1) Water intake stage: Turn on the water intake pump and aeration system I, adopt sequential batch water intake, and according to the designed treatment capacity (1L/cycle), the aquaculture wastewater to be treated is quickly input into the reactor (input flow rate is 0.5L /min), turn off the water inlet pump and keep it for 5min.

(2) Facultative aerobic stage: close the aeration system I, under the action of the carbon source in the sewage, the nitrate nitrogen in the aquaculture wastewater is reduced to nitrite nitrogen, and the nitrite nitrogen is reduced to nitrogen gas, when dORP/dt When it is greater than -5, it is determined that the carbon source in the wastewater is insufficient for complete denitrification, and the carbon source dosing pump is turned on in time to add carbon source to the reactor in a pulsed manner. Continue to use the value of dORP/dt as the basis for judging, and so on, until an appropriate amount of external carbon source is added to ensure complete denitrification, that is, when the dORP/dt value is less than -5, it is determined that the carbon source is sufficient, and the extension is extended for 30 minutes to ensure the smooth progress of denitrification , as shown in Figure 2, after the start of the facultative oxygen phase, if the dORP/dt is greater than -5, it is determined that the amount of carbon source is insufficient. After adding an additional carbon source and maintaining it for 15 minutes, judge the dORP/dt again until the ORP drops rapidly, and the dORP/dt When it is less than -5, it is determined that the carbon source is sufficient. As shown in the ellipse in Figure 2, the addition of carbon source is stopped, and the NO ₂ -N and NO ₃ -N produced by the aerobic unit in the previous cycle of sewage are all reduced to N ₂ .

(3) Aerobic stage: Turn on the aeration system I, NH ₃ -N and COD in the aquaculture wastewater are oxidized to NO ₂ -N, NO ₂ -N is oxidized to NO ₃ -N, when dpH/dt=0 , as shown in the rectangular box in Figure 2, stop the aeration immediately.

(4) Drainage stage: 80 minutes after the start of the above aerobic stage, turn on the peristaltic pump to suction and drain water. The operation mode of the peristaltic pump is to stop for 2 minutes every 8 minutes, and the designed treatment capacity (1L/cycle) of sewage treated in step (2) After the percolation of the flat membrane in the plate and frame membrane module, it is discharged, and the drainage is completed before the end of the aerobic process, and the peristaltic pump and aeration system I are turned off.

In this embodiment, the average time of each cycle is about 230 minutes, the average time of each round of aerobic phase is 150 minutes, the average time of each round of total drainage is 40 minutes, and the pumped water output is about 2 L/h.

In this embodiment, the following two methods are adopted to control the whole nitrification-denitrification process as a short-range nitrification-denitrification process:

1) Optimizing the aeration time method:

In the first 20 days after the stable operation of the reactor, the effluent NH ₃ -N and NO ₂ -N were maintained at a low concentration level, while NO ₃ -N accounted for more than 85% of the total nitrogen (TN), and the removal rate of ammoniacal nitrogen was 90 %above.

As shown in Figure 2, 115 to 220 minutes is the aerobic stage, the NH ₃ -N and COD in the wastewater are oxidized, the pH gradually decreases, and when it reaches the lowest point, which is the ammonia valley point (dpH/dt=0), stop immediately Aeration, as shown in the rectangular box in Figure 2. During the aeration process (115-220min), the concentration of dissolved oxygen in the wastewater is 0.2-3.5mg/L, which is maintained at a low level, and the oxidation rate of ammonia nitrogen (about 15.1mgN/h·L) is much higher than the oxidation rate of nitrous nitrogen (about 2.8mgN/h·L). The level of NO ₂ -N (about 50mg/L) in the reactor effluent was significantly higher than that of NO ₃ -N (about 10mg/L) and NH ₃ -N (<3mg/L), and the nitrosation rate was about 83%.

(2) SRT control method:

In the present embodiment, the average residence time of the control system sludge is 15 days, because the sludge age of the ammonia oxidizing bacteria is generally 10-12 days under the control conditions of the present embodiment (T=25°C, pH≥7.0), while the nitrous acid The sludge age of oxidizing bacteria is generally 18-20 days, which can gradually reduce the number of nitrite oxidizing bacteria, so that the proportion of ammonia oxidizing bacteria in the real nitrifying bacteria group continues to increase, and the nitrification rate can continue to increase.

See Table 2 for the concentration and removal rate of pollutants in the landfill leachate before and after the above-mentioned steps of treatment, that is, the influent and effluent water.

Concentration and removal rate of pollutants in and out of water in table 2 embodiment 3

ND: not detected

Embodiment 4, utilizing sequencing batch type activated sludge process and membrane separation technology to treat sludge digestate

The device in Example 1 is used to process the landfill leachate, and the temperature of the control reactor is 20 ± 0.5 ° C. The treatment process includes the following steps:

Inoculate the return sludge of urban sewage treatment plant with a concentration of 5000mg/L into the reactor, turn on the agitator, aeration system I (aeration flow rate is 5L/min), aeration system II (aeration flow rate is 8L/min ), the water inlet pump and the implementation control system adopt the method of gradient water inlet (sewage) to gradually increase the sludge concentration to 11000mg/L, and the gradient water inlet control is as follows: the first stage is 7 days, and the inlet water is diluted to the original 1/4 of the sewage concentration, the second stage is 7 days, the influent is diluted to 1/2 of the original sewage concentration, the third stage begins, the influent uses the original sewage, and the start-up is completed after 45 days. When the removal rate of ammoniacal nitrogen in the sewage (influent ammonia nitrogen concentration/effluent ammonia nitrogen concentration) is greater than 80%, and the content of nitrate nitrogen in the discharged wastewater accounts for more than 70% of the total nitrogen in the wastewater, the reactor reaches a stable whole process Denitrification, the start-up phase is completed, turn off the water inlet pump and aeration system I, repeat the following steps (1)-step (4) until all waste water is discharged, turn off the agitator, aeration system II and implement the control system:

(1) Water intake stage: Turn on the water intake pump and aeration system I, adopt sequential batch water intake, and according to the designed treatment capacity (1.5L/cycle), the aquaculture wastewater to be treated is quickly input into the reactor (the input flow rate is 0.5 L/min), turn off the water inlet pump and keep it for 5min.

(2) Facultative oxygen stage: close the aeration system, under the action of the carbon source in the sewage, the nitrate nitrogen in the aquaculture wastewater is reduced to nitrite nitrogen, and the nitrite nitrogen is reduced to nitrogen gas. When dORP/dt is greater than At -5, it is determined that the carbon source in the wastewater is insufficient for complete denitrification, and the carbon source dosing pump is turned on in time to add carbon source to the reactor in a pulsed manner. The value of dORP/dt is used as the basis for judgment, and this cycle is repeated until an appropriate amount of external carbon source is added to ensure complete denitrification. That is, when the dORP/dt value is less than -5, it is judged that the carbon source is sufficient and extended for 25 minutes to ensure smooth denitrification.

(3) Aerobic stage: when the aeration system is turned on, NH ₃ -N and COD in the aquaculture wastewater are oxidized to NO ₂ -N, and NO ₂ -N is oxidized to NO ₃ -N.

(4) Drainage stage: 60 minutes after the above-mentioned aerobic stage, start the peristaltic pump to suction and drain water. The operation mode of the peristaltic pump is to stop for 2 minutes every 8 minutes, and the designed processing capacity (1.5L/cycle) is processed by step (2). The sewage is discharged after being filtered by the flat membrane in the flat membrane module, and the drainage is completed before the end of the aerobic process.

In this embodiment, the average time of each cycle is about 200 minutes, the average aerobic time of each cycle is about 135 minutes, the total drainage time of each cycle is 60 minutes, and the pumped water yield is about 2 L/h.

In this embodiment, the following free ammonia controlled accumulation method and SRT control method are adopted to control the whole nitrification-denitrification process as a short-range nitrification-denitrification process, and the process is as follows:

Firstly, the controlled accumulation method of free ammonia was adopted, that is, the concentration of FA was gradually increased to realize the transformation from nitrification to nitrosation in the whole process: in the first 20 days, the NO ₃ -N in the reactor effluent accounted for more than 90% of the TN, and the removal rate of ammoniacal nitrogen was at From the 21st day to the 33rd day, the aeration flow rate of the reactor was reduced from 5L/min to about 0.5L/min, and the free ammonia concentration in the system increased from about 0.3mg/L to 20mg/L (pH =8.9), then adjust the aeration flow back to 3.5 L/min for continuous aeration until NO ₂ /(NO ₂ +NO ₃ ) reaches above 80%. Along with the oxidation of ammonia nitrogen, NO ₂ -N increased to 160mg/L, much higher than NO ₃ -N (the highest was only 40mg/L). After the controlled accumulation of FA, the aerobic unit of the reactor adopts the control method 1) optimize the aeration time, that is, when the pH drops to the ammonia valley point (dpH/dt=0), the aeration is stopped immediately, and the nitrification of continuous operation The rate averaged 82%.

See Table 3 for the concentration and removal rate of pollutants in the sludge digestion liquid before and after the above-mentioned steps, namely the influent and effluent water.

Concentration and removal rate of pollutants in and out of water in table 3 embodiment 4

ND: not detected.

Claims (8)

1. a kind of process high ammonia-nitrogen wastewater device it is characterised in that：It includes water inlet system, aerating system, carbon source add and be System, response system, film separation system and outlet system；

Described response system includes a reactor, and described reactor is a container, and the top of described reactor is provided with agitator；

Described water inlet system includes a raw water box, and described raw water box is connected with described reactor by intake pump；

Described aerating system includes air compressor machine, gas flowmeter and aerator, and described aerator is placed in described reactor；

Described carbon source dosing system includes a carbon source storage tank, and described carbon source storage tank adds pump with described reactor even by carbon source Connect；

Described film separation system is a membrane module；

Described membrane module is placed in the side-walls of described reactor；

Described membrane module is plate and frame module, and described plate and frame module includes 1～2 film unit, each described film unit It is made up of two panels film, the material of described film is Kynoar, aperture≤0.1 μm, and effective area is 0.5m²；Described membrane module Inside be additionally provided with aerator, be connected with another air compressor machine and another gas flowmeter successively, be described film aeration；

Described outlet system includes a product water tank, and the outlet of described membrane module is connected with described product water tank by going out water pump；

Described device also includes a real-time control system, and described enforcement control system includes probe, integrated circuit case and numeral and touches Control plate；

Described probe includes pH probe, ORP probe and dissolved oxygen DO probe, is all connected with described integrated circuit case, described integrated Circuit box is connected with described touch sensitive digitizer panel.

2. the method utilizing the device described in claim 1 to process high ammonia-nitrogen wastewater, comprises the steps：

Inoculation of activated-sludge, to described reactor, opens described agitator, repetitive cycling following step (1)-step (4)：

(1) fill phase：Open described aerating system and described intake pump, using batch-type water inlet, according to Design Treatment amount, treat The described high ammonia-nitrogen wastewater processing is transfused in described reactor, closes described intake pump；

(2) the simultaneous oxygen stage：Close described aerating system, in the presence of carbon source, the nitrate nitrogen in waste water is reduced to nitrous state Nitrogen, nitrite nitrogen is reduced to nitrogen；

(3) aerobic stage：Open described aerating system, the ammoniacal nitrogen in waste water and Organic substance are oxidized, described ammoniacal nitrogen is by oxygen Turn to nitrite nitrogen, nitrite nitrogen is oxidized to nitrate nitrogen；

(4) bleeding stage：After described aerobic stage starts 60～120min, described in unlatching, go out water pump, the institute of Design Treatment amount State waste water to discharge after the filtration of film in described membrane module, go out water pump and described aerating system described in closing successively.

3. method according to claim 2 it is characterised in that：Described real-time control system is whole to open, and monitors described height The size of oxidation-reduction electrode current potential, pH value and dissolved oxygen in ammonia nitrogen waste water；

Aerator in described membrane module is whole to be opened, and aeration flow is 5～15L/min piece.

4. according to the method in claim 2 or 3 it is characterised in that：The concentration of the activated sludge of described inoculation is 5000mg/ L～5500mg/L, gradient improves the influent concentration of sewage, and activated sludge concentration is increased to 10000mg/L～12000mg/L；

Described gradient raising is divided into three phases, and first stage is 5～10, and the 1/4 of water inlet dilution most raw sewage concentration； Second stage is 5～10, and water inlet is diluted to the 1/2 of raw sewage concentration；Three phases are 30～55.

5. according to the method in claim 2 or 3 it is characterised in that：In step (1), ammoniacal nitrogen in described high ammonia-nitrogen wastewater Concentration 500～900mg/L, COD content be 5000～10000mg/L；

Described high ammonia-nitrogen wastewater is derived from livestock breeding wastewater, percolate or sludge-digestion liquid；

Described Design Treatment amount is 0.5～1.5L/cycle；

The flow of described input is 0.5～1L/min；

Pending described high ammonia-nitrogen wastewater is transfused to after keeping 3～5min in described reactor and enters the described and oxygen stage.

6. according to the method in claim 2 or 3 it is characterised in that：In step (2), when the oxidation-reduction electrode electricity of waste water Position over time value be dORP/dt be 0～-5 when, judge carbon source deficiency, unlatching described carbon source add pump, be described reaction Device adds carbon source, and each opening time is 0.5～1min, after keeping 10～20min, enters and judges next time；As described dORP/ When dt is less than -5, after time delay 10～30min, open described aerating system, enter in step (3).

7. according to the method in claim 2 or 3 it is characterised in that：In step (3), time of described aerobic stage is 9～ 180min, aeration flow is 0.5～10L/min；

In step (4), time of described bleeding stage is 30～90min, described go out water pump be batch (-type) suction, often open 8～10 Minute stops 2～4 minutes.

8. according to the method in claim 2 or 3 it is characterised in that：Using following 1) -3) at least one of method by whole process Nitrification-denitrification is converted into short-cut nitrification-denitrification：

1) optimize aeration time method：After denitrogenation is stable, in the described aerobic stage of every wheel circulation, when the pH value in waste water in time Do not change i.e. dpH/dt=0 when, close described aerating system；

2) the controlled method of cumulative scale of free ammonia：After denitrogenation is stable, in described aerobic stage, reduce the aeration flow of described aerating system, When the concentration of ammonia free in waste water raises to above equal to 20mg/L, recover aeration flow；

Aeration flow in the whole circulation of described aerating system is reduced to 0.2～1L/min；

Above-mentioned 1) and 2) described in denitrogenation stably each mean when the ammoniacal nitrogen in described waste water clearance be more than 80%, and arrange When nitrate nitrogen in the waste water going out accounts for the content of described Determination of Total Nitrogen in Waste Water more than 70%；

3) SRT control methods：The step that methods described also includes spoil disposal, described spoil disposal, after described aerobic stage, controls described The mean residence time of the mud in reactor is 12～15 days.