CN-122010297-A - NDFO reactor based on synergistic regulation and control of chelating agent and quorum sensing signal molecules and iron crusting prevention method

CN122010297ACN 122010297 ACN122010297 ACN 122010297ACN-122010297-A

Abstract

The invention provides a NDFO reactor and an iron-crusting-resistant method based on synergistic regulation and control of a chelating agent and quorum sensing signal molecules, wherein the reactor comprises a main reactor, a stirring and solid-liquid-gas separation device, an anaerobic maintenance device, a temperature regulating device and a medicament adding device. The medicament adding device is provided with two independent loops for adding the chelating agent and the quorum sensing signal molecules. The method comprises the steps of adding a reagent in three stages after a reactor starts and stably runs, adding a signal molecule and a strong chelating agent in stage I to quickly break the shell and release iron when iron crust occurs, reducing the concentration of the signal molecule and changing the concentration to a mild complexing agent in stage II, gradually stopping the signal molecule in stage III, maintaining the mild complexing agent, and promoting structural reconstruction and performance recovery. The scheme can effectively break NDFO system iron crusts, recover denitrification performance, has the advantages of controllable operation and convenient maintenance, and is suitable for low-carbon denitrification treatment of iron-containing wastewater.

Inventors

WANG YUJIA
FU QIANG
GAO YI
LV ZE
LI WEI
HUANG XUAN
WANG XUEYUN
FENG WEIYANG
LIU JUNNAN
LIU YUHAN

Assignees

沈阳建筑大学

Dates

Publication Date: 20260512
Application Date: 20260204

Claims (11)

1. A NDFO reactor based on synergistic regulation and control of chelating agent and quorum sensing signal molecules is characterized by comprising a water inlet and outlet reaction tank, an aeration and stirring device, an anaerobic maintaining device, a solid-liquid-gas separation and collection device, a temperature regulating device and a medicament adding device.
2. The water inlet and outlet reaction tank comprises a main body reactor, a water inlet unit and a water outlet unit; The main reactor is a continuous stirring reactor and is provided with an inner layer and an outer layer, the inner layer is a microbial reaction layer, and the outer layer is a heat preservation layer or a circulating jacket layer; The water inlet unit is connected with the water inlet at the upper part of the main body reactor through a water inlet pump and is used for continuously or intermittently quantitatively feeding water; the medicament adding device is used for adding chelating agent and/or quorum sensing signal molecules to the reactor, and an adding pipeline of the medicament adding device is communicated with the water inlet unit and/or a side wall interface of the main reactor; The stirring and solid-liquid-gas separation device comprises a stirring motor, a three-phase separator, a gas collecting bottle and a gas collecting bag, wherein the stirring motor is arranged at the top of the main body reactor and is connected with a stirring paddle through a stirring shaft; the gas collecting bottle is connected between a gas phase outlet of the three-phase separator and the gas collecting bag, is used for intercepting entrained liquid drops and buffering gas flow, and the gas collecting bag is used for collecting gas generated by the reaction; the anaerobic maintaining device comprises a nitrogen steel bottle, a gas washing bottle and an aeration disc; The nitrogen steel cylinder is sequentially connected with a pressure regulator and a gas washing cylinder through a gas pipeline, and finally is introduced into an aeration disc arranged in the main reactor; a gas flowmeter is arranged between the nitrogen steel cylinder and the gas washing cylinder; The pressure regulator is used for regulating the stirring rotation speed to ensure that mixed liquid in the reactor is uniformly mixed, the aeration disc is used for introducing inert gas into the reactor to replace oxygen and maintain anaerobic or anoxic environment, and the nitrogen enters the gas washing bottle through the gas flowmeter and then is introduced into the main reactor to replace headspace and/or liquid-phase dissolved oxygen of the reactor and maintain the system in a light-resistant anaerobic state; The temperature regulating device consists of a circulating water bath thermostat, and the circulating water bath thermostat is communicated with an outer jacket or an outer circulating pipeline of the main reactor through a circulating pipeline to form a circulating constant temperature loop and control the reaction temperature; The medicament adding device comprises a medicament liquid storage container, a signal molecule solution box and a medicament adding and adding pipe, wherein an outlet of the adding pipe is connected to a water inlet pipe of the water inlet unit and/or a side wall/top interface of the main body reactor.
3. The NDFO reactor based on the synergistic regulation and control of the chelating agent and the quorum sensing signal molecules as set forth in claim 1, wherein the reagent adding device is provided with two independent adding loops for adding the chelating agent and the quorum sensing signal molecules respectively.
4. The NDFO reactor based on the synergistic regulation and control of the chelating agent and the quorum sensing signal molecules, which is disclosed in claim 2, is characterized in that a feeding pipeline for feeding the chelating agent is communicated with a water inlet pipeline of the water inlet unit, and the feeding pipeline for feeding the quorum sensing signal molecules is connected with a plurality of feeding valves which are arranged at different heights and/or at the top of the side wall of the main reactor.
5. The NDFO reactor based on the synergistic regulation and control of chelating agent and quorum sensing signal molecules as set forth in claim 3, wherein the adding pipeline is provided with a check valve or a one-way valve for preventing the reaction liquid from flowing backwards.
6. The NDFO reactor based on the synergistic regulation and control of chelating agents and quorum sensing signal molecules as set forth in claim 3, wherein the side wall of the main reactor is provided with a plurality of interfaces, including sampling ports and/or sludge discharge ports, the sampling ports are used for running monitoring and sampling, the sludge discharge ports are used for discharging deposited sludge, and signal molecule adding valves are arranged at different heights of the reactor to realize regional adding; The water outlet unit is provided with a water outlet valve for adjusting water outlet or sampling discharge.
7. The NDFO reactor and the anti-iron crusting method based on the synergistic regulation of chelating agents and quorum sensing signal molecules according to any one of claims 1 to 5, comprising the steps of: Step S1, starting and stably operating a reactor, namely inoculating anaerobic sludge with NDFO functions into a main reactor, introducing nitrogen to maintain an anaerobic environment, controlling the reaction temperature to be 25-35 ℃, controlling the pH to be 6.0-7.2, controlling the hydraulic retention time to be 6-24 hours, and continuously operating by taking nitrate as an electron acceptor and Fe & lt2+ & gt as an electron donor; and S2, implementing cooperative crust breaking and performance recovery strengthening operation, namely adding a medicament into the reactor according to the following three stages when the iron crust formation characteristic of the reactor appears: Stage I, namely, in the stage of rapid shell breaking and iron release, adding quorum sensing signal molecules and a strong complexing type chelating agent into a reactor; a stage II of steady-state transition and mild regulation, wherein the concentration of the quorum sensing signal molecules is reduced, and the addition of the strong complexing chelating agent is stopped, and the addition of the heating and complexing agent is changed into the addition of the strong complexing agent; And step III, in the structure reconstruction and consolidation step, gradually reducing and finally stopping adding the quorum sensing signal molecules, and maintaining adding the mild complexing agent or converting into intermittent adding until the denitrification performance of the system is recovered and stabilized.
8. The NDFO reactor and the anti-iron crusting method based on the synergistic regulation and control of the chelating agent and the quorum sensing signal molecules according to claim 6, wherein in the step S1, the reaction temperature is 31 ℃, the pH is preferably 6.4-6.8, the hydraulic retention time is preferably 12 hours, and the molar ratio of Fe 2+ to NO 3 - is controlled to be 2:1-4:1.
9. The NDFO reactor and the anti-iron crusting method based on the synergistic regulation and control of the chelating agent and the quorum sensing signal molecules, which are disclosed in claim 6, are characterized in that in the stage I of the step S2, the quorum sensing signal molecules are AHLs signal molecules, the adding concentration is 100-200 nM, the strong complexing chelating agent is EDTA or DTPA, and the adding amount is controlled according to the molar ratio of 0.5:1 to 1:1 with Fe 3+ in the system; In the stage II, the adding concentration of the quorum sensing signal molecules is reduced to 50-100 nM, the mild complexing agent is sodium citrate, and the adding amount of the mild complexing agent is controlled according to the mol ratio of the mild complexing agent to the inflow water Fe 2+ of 1:1-2:1.
10. The NDFO reactor and the anti-iron crusting method based on the synergistic regulation and control of the chelating agent and the quorum sensing signal molecules, which are disclosed in claim 8, are characterized in that the AHLs signal molecules are preferably C6-HSL, the adding concentration is preferably 100 nM, and the molar ratio of the strong complexing chelating agent to Fe 3+ is preferably 1:1; The addition concentration of the quorum sensing signal molecules is preferably 100 nM, and the molar ratio of the sodium citrate to the Fe 2+ is preferably 2:1.
11. The NDFO reactor and the iron crusting resistance method based on the synergistic regulation and control of the chelating agent and the quorum sensing signal molecules, which are disclosed in claim 6, are characterized in that the iron crusting characteristics comprise one or more of thickening of a reddish brown coating on the surface of sludge, increasing of the concentration of Fe 3+ in effluent, decreasing or fluctuation increasing of nitrate nitrogen removal rate and poor sludge sedimentation performance.

Description

NDFO reactor based on synergistic regulation and control of chelating agent and quorum sensing signal molecules and iron crusting prevention method Technical Field The invention belongs to the technical field of environmental engineering and water pollution control, and particularly relates to a NDFO reactor and an anti-iron crusting method based on synergistic regulation and control of a chelating agent and quorum sensing signal molecules. Background The discharge of the nitrogenous wastewater can easily lead to water body eutrophication and other environmental problems. The NDFO process adopts Fe 2+ as an electron donor to drive nitrate to reduce, has the characteristics of no need of externally adding an organic carbon source, low sludge yield and the like, and has good low-carbon denitrification application prospect. However, the problem of iron crusting (Fe (III) deposition layer) is common in long-term operation of NDFO systems, namely Fe 2+ is continuously oxidized to generate Fe (III) and is deposited on the surface of granular sludge/EPS, so that a composite limiting structure of an inorganic deposition shell layer and an Fe-EPS adhesion layer is gradually formed, and mass transfer limitation, electron transfer blockage, particle densification or disintegration, system denitrification performance reduction and even operation instability are caused. The existing method for relieving crust is mostly dependent on measures such as sludge replacement, shearing improvement, chemical cleaning or pH/redox impact and the like, and often has the defects of complex operation, large disturbance on microbial activity, long recovery period, easiness in secondary influence and the like. The chelating agent alone can mobilize and deposit iron, but can bring about too strong complexation, increase of addition cost or influence on the balance of trace metals of the system, and the biological regulation (such as promoting EPS secretion) alone can have the problems of slow effect and insufficient removal of formed compact shell layers. Thus, there is a need for a crust removal and performance recovery process that is controllable, sustainable, milder to system disturbances, and can be directly performed at run-time. Disclosure of Invention In order to solve the technical problems, the invention aims to provide a NDFO reactor and an anti-iron crusting method based on synergistic regulation and control of a chelating agent and quorum sensing signal molecules, which have the following specific technical scheme: A NDFO reactor based on synergistic regulation and control of chelating agent and quorum sensing signal molecules is characterized by comprising a water inlet and outlet reaction tank, an aeration and stirring device, an anaerobic maintaining device, a solid-liquid-gas separation and collection device, a temperature regulating device and a medicament adding device. The water inlet and outlet reaction tank comprises a main body reactor, a water inlet unit and a water outlet unit; The main reactor is a continuous stirring reactor and is provided with an inner layer and an outer layer, the inner layer is a microbial reaction layer, and the outer layer is a heat preservation layer or a circulating jacket layer; The water inlet unit is connected with the water inlet at the upper part of the main body reactor through a water inlet pump and is used for continuously or intermittently quantitatively feeding water; the medicament adding device is used for adding chelating agent and/or quorum sensing signal molecules to the reactor, and an adding pipeline of the medicament adding device is communicated with the water inlet unit and/or a side wall interface of the main reactor; The stirring and solid-liquid-gas separation device comprises a stirring motor, a three-phase separator, a gas collecting bottle and a gas collecting bag, wherein the stirring motor is arranged at the top of the main body reactor and is connected with a stirring paddle through a stirring shaft; the gas collecting bottle is connected between a gas phase outlet of the three-phase separator and the gas collecting bag, is used for intercepting entrained liquid drops and buffering gas flow, and the gas collecting bag is used for collecting gas generated by the reaction; the anaerobic maintaining device comprises a nitrogen steel bottle, a gas washing bottle and an aeration disc; The nitrogen steel cylinder is sequentially connected with a pressure regulator and a gas washing cylinder through a gas pipeline, and finally is introduced into an aeration disc arranged in the main reactor; a gas flowmeter is arranged between the nitrogen steel cylinder and the gas washing cylinder; The pressure regulator is used for regulating the stirring rotation speed to ensure that mixed liquid in the reactor is uniformly mixed, the aeration disc is used for introducing inert gas into the reactor to replace oxygen and maintain anaerobic or anoxic environment, and the nitrog