A rapid domestication device and method for 2,4,6-trichlorophenol-degrading functional bacteria

Abstract

The present invention relates to a rapid domestication device and method for 2,4,6-trichlorophenol-degrading functional bacteria. The present invention is applicable to the technical field of wastewater biological treatment. The technical problem to be solved by the present invention is: to provide a rapid domestication device and method for 2,4,6-trichlorophenol-degrading functional bacteria. The technical solution adopted by the present invention is: a rapid domestication system for 2,4,6-trichlorophenol-degrading functional bacteria, characterized in that it includes: a chlorophenol inlet water tank; an aeration tank having a closed chamber; a stripping gas collection tank connected to the aeration tank through a gas transmission pipe; an upflow chlorophenol degradation reactor, which is vertically separated into a plurality of reaction chambers by a plurality of microfiltration membranes capable of retaining bacteria; a reflux pipe connecting the overflow tank and the aeration tank, and a reflux pump is equipped thereon; an outlet water tank connected to the overflow tank through a drain pipe; a control unit, which is electrically connected to the water supply pump, the water transmission pump, the reflux pump, and an aeration device and a dissolved oxygen detector installed in the aeration tank.

Description

Technical Field

[0001] The present invention relates to a rapid domestication device and method for 2,4,6-trichlorophenol-degrading functional bacteria, and is applicable to the technical field of wastewater biological treatment. Background Art

[0002] Chlorophenols are mainly used in the industrial production of products such as dye intermediates, pesticides, and preservatives. Due to non-compliant emissions, they often appear in the wastewater of industries such as printing and dyeing and wood preservation, and already exist in natural water bodies.

[0003] As a widely used industrial raw material, 2,4,6-trichlorophenol has "three carcinogenic" effects on the human body, belongs to toxic organic substances, and has been listed as a priority controlled pollutant. It is urgent to establish an effective treatment technology method for treating toxic wastewater containing 2,4,6-trichlorophenol.

[0004] Chinese Patent CN201811504868.X discloses a method for rapidly domesticating microorganisms capable of degrading 2,4,6-trichlorophenol. The method utilizes the principle of co-metabolism to achieve the degradation and removal of 2,4,6-trichlorophenol under aerobic conditions with the addition of easily degradable carbon sources. Although this method can achieve the rapid domestication of functional bacteria, a large amount of 2,4,6-trichlorophenol toxic gas will be blown into the air during the aeration process of high dissolved oxygen, seriously polluting the environment. In addition, the device only uses a sequencing batch reactor (SBR) as the main reaction equipment, and there are problems of mutual inhibition between carbon source metabolism and chlorophenol co-metabolism, reducing the degradation efficiency of 2,4,6-trichlorophenol and unable to maintain high-efficiency and stable degradation.

[0005] Chinese Patent CN201910377488.2 discloses a method for domesticating microorganisms capable of co-metabolically degrading 2,4,6-trichlorophenol using domestic sewage as a carbon source. The method replaces traditional commercial carbon sources with domestic sewage, achieving zero addition of external commercial carbon sources and significantly reducing the operation and maintenance costs of 2,4,6-trichlorophenol degradation. However, during the chlorophenol degradation process, the competition between carbon source metabolism and chlorophenol co-metabolism and the chlorophenol stripping problem still cannot be avoided. Summary of the Invention

[0006] The technical problem to be solved by the present invention is: in view of the above problems, to provide a rapid domestication device and method for 2,4,6-trichlorophenol-degrading functional bacteria.

[0007] The technical solution adopted by the present invention is: a rapid domestication system for 2,4,6-trichlorophenol-degrading functional bacteria, characterized by comprising:

[0008] A chlorophenol inlet water tank for collecting toxic wastewater containing 2,4,6-trichlorophenol;

[0009] An aeration tank having a sealed chamber which is connected to the chlorophenol inlet water tank through a water supply pipe equipped with a water supply pump;

[0010] A stripping gas collection tank which is connected to the aeration tank through a gas transmission pipe and is communicated with the top of the sealed chamber in the aeration tank;

[0011] An upflow chlorophenol degradation reactor in which a plurality of reaction chambers are vertically separated by a number of microfiltration membranes capable of intercepting bacteria. The bottom of the reactor is connected to the lower part of the aeration tank through a water transmission pipe equipped with a water transmission pump, and an overflow tank for collecting the overflow water at the top end of the reactor is provided at the top of the reactor;

[0012] A reflux pipe which communicates the overflow tank and the aeration tank and is equipped with a reflux pump thereon;

[0013] An outlet water tank which is communicated with the overflow tank through a drain pipe;

[0014] A control unit which is circuit-connected to the water supply pump, the water transmission pump, the reflux pump, an aeration device and a dissolved oxygen detector installed in the aeration tank.

[0015] The stripping gas collection tank is filled with a sodium hydroxide solution, and the gas outlet of the gas transmission pipe is connected with a diffuser which is submerged in the sodium hydroxide solution in the stripping gas collection tank.

[0016] The concentration of the sodium hydroxide solution is 20 - 25 mg / L.

[0017] The upflow chlorophenol degradation reactor has a reactor main body. The lower end of the reactor main body is an inlet, the upper end of the reactor main body is an opening, and a number of the reaction chambers are arranged between the upper and lower ends of the reactor main body;

[0018] A circle of the overflow tank surrounding the top opening is provided on the periphery of the top of the reactor main body, and a reactor cover plate is provided above the reactor main body, and the reactor cover plate is connected to the outer side wall of the overflow tank.

[0019] The microfiltration membrane adopts a polytetrafluoroethylene microfiltration membrane.

[0020] A rapid acclimation method based on the rapid acclimation system, characterized in that:

[0021] S1. Inoculate the 2,4,6-trichlorophenol co-metabolic degradation bacteria into each reaction chamber of the upflow chlorophenol degradation reactor;

[0022] S2. Pump the toxic wastewater with a 2,4,6-trichlorophenol concentration of 10 mg / L in the chlorophenol inlet water tank into the aeration tank;

[0023] S3. Increase the dissolved oxygen concentration of the toxic wastewater through the aeration device in the aeration tank, close the aeration device after the dissolved oxygen concentration of the toxic wastewater is increased to the preset concentration, and pump the toxic wastewater in the aeration tank to the up-flow chlorophenol degradation reactor;

[0024] S4. Pump the water body in the overflow tank back into the aeration tank through the reflux pipe and the reflux pump;

[0025] S5. Repeat steps S3 and S4 until 2,4,6-trichlorophenol in the water body in the overflow tank is completely degraded;

[0026] S6. Discharge the water body in the overflow tank to the outlet water tank;

[0027] S7. Gradually increase the concentration of 2,4,6-trichlorophenol in the chlorophenol inlet water tank, and after each concentration increase, return to step S2 to pump the toxic wastewater with the increased concentration into the aeration tank until the concentration of 2,4,6-trichlorophenol is increased to 300 mg / L.

[0028] A microbial nutrient solution and ammonia nitrogen are added to the chlorophenol inlet water tank.

[0029] KH2PO4·3H2O, K2HPO4, MgSO4·7H2O, FeSO4·7H2O and CaCl2·2H2O are also added to the chlorophenol inlet water tank.

[0030] In step S1, the inoculation concentration of the 2,4,6-trichlorophenol co-metabolic degradation bacteria is 2000 - 3000 mg / L.

[0031] The preset dissolved oxygen concentration in the aeration tank is 5.5 mg / L; the flow rate of the water pump is 200 mL / min.

[0032] The beneficial effects of the present invention are as follows: The present invention can intercept 2,4,6-trichlorophenol degradation bacteria through the microfiltration membrane, avoiding the problems of small cell aggregation and sludge loss caused by no other carbon source input. In addition, the interception effect also significantly improves the concentration and degradation effect of 2,4,6-trichlorophenol degradation bacteria.

[0033] The present invention avoids the problem of 2,4,6-trichlorophenol polluting the air caused by oxygenation aeration by setting up a stripping gas collection box.

[0034] The 2,4,6-trichlorophenol degradation bacteria domesticated by the present invention can completely use 2,4,6-trichlorophenol as a carbon source without adding other carbon sources, saving a large amount of carbon sources. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic structural diagram of the system for the embodiment.

[0036] 1. Chlorophenol inlet tank; 2. Aeration tank; 3. Stripped gas collection tank; 4. Upflow chlorophenol degradation reactor; 5. Outlet tank; 6. Control unit; 1.1. Outlet of the inlet tank; 2.1. Inlet for aeration; 2.2. Dissolved oxygen detector; 2.3. Outlet for aeration gas; 2.4. Outlet of aeration; 2.5. Air flow meter; 2.6. Aeration pump; 2.7. Micro-porous aeration disc; 3.1. Outlet of the collection tank; 3.2. Diffuser; 4.1. Overflow return port; 4.2. Overflow outlet; 4.3. Microfiltration membrane; 4.4. Inlet of the reactor; 5.1. Inlet of the outlet tank; 5.2. Drain of the outlet tank; 6.1. Computer; 6.2. Sensor and signal converter; 1-1. Water supply pump; 2-1. Water transfer pump; 4-1. Return pump. Detailed implementation mode

[0037] As Figure 1 shown, this embodiment is a rapid domestication system for functional bacteria degrading 2,4,6-trichlorophenol, including a chlorophenol inlet tank, an aeration tank, a stripped gas collection tank, an upflow chlorophenol degradation reactor, an outlet tank, a control unit, etc.

[0038] In this example, the chlorophenol inlet tank is used to collect the toxic wastewater containing 2,4,6-trichlorophenol. The outlet of the inlet tank of the chlorophenol inlet tank is connected to the inlet for aeration of the aeration tank through a water supply pipe, and a water supply pump is installed on the water supply pipe to transport the water in the inlet tank to the aeration tank through the water supply pump.

[0039] In this embodiment, the aeration tank has a sealed chamber inside. An aeration device is provided at the bottom of the sealed chamber. The top of the sealed chamber is connected to one end of an air delivery pipe through an outlet for aeration gas. The other end of the air delivery pipe is connected with a diffuser, which is placed in the stripped gas collection tank. The stripped gas collection tank is filled with sodium hydroxide solution, and the sodium hydroxide solution submerges the diffuser.

[0040] In this embodiment, the aeration device includes an air flow meter, an aeration pump and a micro-porous aeration disc. The micro-porous aeration disc is arranged at the bottom inside the sealed chamber. The aeration pump outside the aeration tank is connected to the micro-porous aeration disc inside the aeration tank through an air delivery pipe and an air flow meter.

[0041] In this example, a dissolved oxygen detector is provided corresponding to the aeration tank. The detection probe of the dissolved oxygen detector is placed inside the sealed chamber of the aeration tank to collect the dissolved oxygen concentration of the water body in the aeration tank.

[0042] In this example, the outlet of aeration of the aeration tank is connected to the inlet of the reactor at the lower end of the upflow chlorophenol degradation reactor through a water delivery pipe, and a water transfer pump is installed on the water delivery pipe to transport the water in the aeration tank to the upflow chlorophenol degradation reactor through the water transfer pump.

[0043] In this embodiment, the up-flow chlorophenol degradation reactor has a reactor main body. The lower end of the reactor main body is the reactor water inlet, and the upper end of the reactor main body is an opening. Inside the reactor main body, several reaction chambers are vertically separated by a number of polytetrafluoroethylene microfiltration membranes capable of retaining bacteria. A overflow trough surrounding the reactor main body is provided outside the top of the reactor main body.

[0044] In this example, a cover plate is provided above the reactor main body. An overflow channel is formed between the cover plate and the side wall of the lower reactor main body. The cover plate is fixed to the outer wall of the overflow trough.

[0045] In this embodiment, the overflow trough is connected to one end of a reflux pipe through an overflow return port at the bottom of the overflow trough. The other end of the reflux pipe extends into the sealed chamber of the aeration tank, and a reflux pump is installed on the reflux pipe.

[0046] In this example, the overflow trough is connected to a drain pipe through an overflow water outlet at the bottom of the overflow trough, and is connected to the water inlet of the water outlet tank through the drain pipe.

[0047] In this embodiment, the control unit includes a computer, a sensor, and a signal converter. The computer is circuit-connected to a water supply pump, a water transfer pump, a reflux pump, an aeration pump, a dissolved oxygen detector, etc. through the sensor and the signal converter to obtain the dissolved oxygen concentration data collected by the dissolved oxygen detector, and control the start and stop of the water supply pump, the water transfer pump, the reflux pump, and the aeration pump.

[0048] In this example, during the domestication of functional bacteria, the concentration of 2,4,6-trichlorophenol in the chlorophenol inlet water tank is 10 mg / L to 310 mg / L. When domestication is carried out for the first time, the concentration of 2,4,6-trichlorophenol in the chlorophenol inlet water tank is 10 mg / L. The water inlet is carried out in a manner of increasing the concentration gradient, which is adjusted by an on-line control system. In addition to 2,4,6-trichlorophenol in the influent water, a microbial nutrient solution is added additionally. Ammonia nitrogen is prepared with ammonium sulfate and tap water, and the ammonia nitrogen concentration is kept at 10 mg / L. Other nutrient elements are shown in Table 1:

[0049] Table 1 Ratio of other nutrient elements in the influent water

[0050] Serial number Component Concentration (mg / L) 1 <![CDATA[KH2PO4.3H2O]]> 5.5 2 <![CDATA[K2HPO4]]> 7.5 3 <![CDATA[MgSO4.7H2O]]> 22 4 <![CDATA[FeSO4.7H2O]]> 5 5 <![CDATA[CaCl2.2H2O]]> 35

[0051] In this embodiment, a rapid domestication method for 2,4,6-trichlorophenol-degrading functional bacteria includes the following steps:

[0052] S1. Inoculate 2,4,6-trichlorophenol co-metabolic degrading bacteria (low-concentration degrading bacteria) into the up-flow chlorophenol degradation reactor, and the inoculation concentration is 2000 - 3000 mg / L. The functional bacteria are enclosed in the reaction chamber composed of the polytetrafluoroethylene microfiltration membrane and the up-flow chlorophenol degradation reactor. The microfiltration membrane can retain bacteria and only allow the circulating water containing 2,4,6-trichlorophenol and nutrient solution to pass through.

[0053] The stripping gas collection tank is filled with sodium hydroxide solution at a concentration of 20 - 25 mg / L, and the filling amount is sufficient to submerge the diffuser, which is used to adsorb 2,4,6-trichlorophenol stripped by aeration.

[0054] S2. Pump the toxic wastewater containing 2,4,6-trichlorophenol in the chlorophenol inlet water tank into the aeration tank through a water supply pump and a water supply pipe.

[0055] S3. Increase the dissolved oxygen concentration of the toxic wastewater through the aeration device in the aeration tank. After the dissolved oxygen concentration of the toxic wastewater is increased to 5.5 mg / L, turn off the aeration pump of the aeration device, and pump the toxic wastewater in the aeration tank to the up-flow chlorophenol degradation reactor through a water transfer pump. The water transfer pump uses a peristaltic pump with a flow rate of 200 mL / min.

[0056] The toxic wastewater enters the up-flow chlorophenol degradation reactor from bottom to top, flows through each microfiltration membrane in turn, and then overflows from the top of the reactor main body into the overflow tank.

[0057] S4. Through the reflux pipe and the reflux pump, pump the outlet water containing undegraded 2,4,6-trichlorophenol overflowing from the up-flow chlorophenol degradation reactor in the overflow tank back into the aeration tank for continued oxygenation.

[0058] S5. Repeat steps S3 and S4 until 2,4,6-trichlorophenol in the water body in the overflow tank has been completely degraded.

[0059] S6. Drain the water body in the overflow tank into the outlet water tank.

[0060] S7. Gradually increase the concentration of 2,4,6-trichlorophenol in the chlorophenol inlet water tank, and after each concentration increase, return to step S2 and repeat steps S2 - S6 to pump the toxic wastewater with increased concentration into the aeration tank until the concentration of 2,4,6-trichlorophenol increases to 300 mg / L. After the toxic wastewater with a 2,4,6-trichlorophenol concentration of 300 mg / L completes steps S2 - S6, it indicates that the functional bacteria have been domesticated.

[0061] This embodiment can complete the degradation of 300 mg / L of 2,4,6-trichlorophenol within 15 days, and the effluent COD is stably lower than 10 mg / L. Compared with the prior arts CN201910377488.2 and CN201811504868.X, the 2,4,6-trichlorophenol-degrading bacteria domesticated in this embodiment have higher purity and significantly improved degradation effect; no additional carbon source needs to be added during the stable operation stage, saving the later operation cost. This embodiment can achieve the rapid domestication and efficient degradation of chlorophenol-degrading bacteria.

Claims

1. A rapid domestication method for a rapid domestication device of 2,4,6-trichlorophenol-degrading functional bacteria, characterized in that, The rapid domestication device for the 2,4,6-trichlorophenol-degrading functional bacteria includes: A chlorophenol inlet water tank for collecting the toxic wastewater containing 2,4,6-trichlorophenol; An aeration tank with a closed chamber, and the closed chamber is connected to the chlorophenol inlet water tank through a water supply pipe equipped with a water supply pump; A stripping gas collection tank connected to the aeration tank through a gas transmission pipe and communicating with the top of the closed chamber in the aeration tank; An upflow chlorophenol degradation reactor, which is vertically separated into several reaction chambers by a number of microfiltration membranes capable of intercepting bacteria. The bottom of the reactor is connected to the lower part of the aeration tank through a water transmission pipe equipped with a water delivery pump, and an overflow tank for collecting the overflow water at the top end of the reactor is provided at the top of the reactor; A reflux pipe connecting the overflow tank and the aeration tank, and a reflux pump is equipped on it; An outlet water tank connected to the overflow tank through a drain pipe; A control unit is circuit-connected to the water supply pump, the water delivery pump, the reflux pump, the aeration device and the dissolved oxygen detector installed in the aeration tank; The rapid domestication method includes: S1. Inoculate the 2,4,6-trichlorophenol co-metabolic degradation bacteria into each reaction chamber of the upflow chlorophenol degradation reactor; S2. Pump the toxic wastewater with a 2,4,6-trichlorophenol concentration of 10 mg / L in the chlorophenol inlet water tank into the aeration tank; S3. Increase the dissolved oxygen concentration of the toxic wastewater through the aeration device in the aeration tank, and turn off the aeration device after the dissolved oxygen concentration of the toxic wastewater is increased to the preset concentration, and pump the toxic wastewater in the aeration tank to the upflow chlorophenol degradation reactor; S4. Pump the water body in the overflow tank back into the aeration tank through the reflux pipe and the reflux pump; S5. Repeat steps S3 and S4 until the 2,4,6-trichlorophenol in the water body in the overflow tank is completely degraded; S6. Drain the water body in the overflow tank into the outlet water tank; S7. Gradually increase the concentration of 2,4,6-trichlorophenol in the chlorophenol inlet water tank, and after each concentration increase, return to step S2 to pump the toxic wastewater with the increased concentration into the aeration tank until the 2,4,6-trichlorophenol concentration is increased to 300 mg / L.

2. The rapid domestication method according to claim 1, wherein: The stripping gas collection tank is filled with sodium hydroxide solution, and the gas outlet of the gas transmission pipe is connected with a diffuser, and the diffuser is submerged in the sodium hydroxide solution in the stripping gas collection tank.

3. The rapid domestication method according to claim 2, characterized in that: The concentration of the sodium hydroxide solution is 20-25 mg / L.

4. The rapid domestication method according to claim 1, wherein: The upflow chlorophenol degradation reactor has a reactor main body, the lower end of the reactor main body is the water inlet, the upper end of the reactor main body is an opening, and between the upper and lower ends of the reactor main body are several of the reaction chambers; A circle of the overflow tank surrounding the top opening is provided on the periphery of the top of the reactor main body, and a reactor cover plate is provided above the reactor main body, and the reactor cover plate is connected to the outer side wall of the overflow tank.

5. The rapid domestication method according to claim 1, characterized in that: The microfiltration membrane uses a polytetrafluoroethylene microfiltration membrane.

6. The rapid domestication method according to claim 1, characterized in that: Microbial nutrient solution and ammonia nitrogen are added to the chlorophenol inlet water tank.

7. The rapid domestication method according to claim 6, characterized in that, KH2PO4·3H2O, K2HPO4, MgSO4·7H2O, FeSO4·7H2O and CaCl2·2H2O are also added to the chlorophenol inlet water tank.

8. The rapid domestication method according to claim 1, characterized in that: In step S1, the inoculation concentration of the 2,4,6-trichlorophenol co-metabolic degradation bacteria is 2000-3000 mg / L.

9. The rapid domestication method according to claim 1, wherein: The preset dissolved oxygen concentration in the aeration tank is 5.5 mg / L; the flow rate of the water pump is 200 mL / min.

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