CN108545827B

CN108545827B - Process for realizing stable short-cut nitrification of town wastewater

Info

Publication number: CN108545827B
Application number: CN201810454938.9A
Authority: CN
Inventors: 刘思彤; 俞开昌; 薛涛; 李天玉; 袁璐璐
Original assignee: Beijing Institute Of Collaborative Innovation; Beijing Originwater Membrane Technology Co Ltd
Current assignee: Beijing Originwater Membrane Technology Co Ltd
Priority date: 2018-05-14
Filing date: 2018-05-14
Publication date: 2020-12-04
Anticipated expiration: 2038-05-14
Also published as: CN108545827A

Abstract

The invention provides a process for realizing stable short-cut nitrification of town wastewater. The process adopts a fixed biological membrane-activated sludge technology combined with an on-line monitoring technology and a sequencing batch activated sludge method to treat the town wastewater so as to achieve the aim of realizing stable shortcut nitrification. The fixed biological membrane-activated sludge technology comprises nitrifying sludge in a fixed state and a suspended state, wherein the nitrifying sludge in the fixed state is realized by biofilm formation, and the nitrifying sludge in the suspended state is realized by controlling the hydraulic retention time and the stirring rotating speed of the SBR technology. The on-line monitoring technology comprises the steps of monitoring the ammonia nitrogen concentration, the nitrate nitrogen concentration, the dissolved oxygen concentration, the pH value and the oxidation-reduction potential in the reactor in real time. The invention can effectively control the abundance and the activity of ammonia oxidizing bacteria in the nitrified sludge by combining the IFAS with the SBR technology, elute the nitrosation oxidizing bacteria and inhibit the activity of the nitrosation oxidizing bacteria, and simultaneously regulate and control the aeration quantity and four procedures of the SBR in real time according to the data monitored on line so as to realize the long-term stable short-cut nitrification effect.

Description

Process for realizing stable short-cut nitrification of town wastewater

Technical Field

The invention relates to the field of treatment of town wastewater, in particular to a process for controlling shortcut nitrification by combining a sequencing batch zeolite fixed biofilm-activated sludge technology with an online monitoring technology.

Background

As a novel biological denitrification process, the partial nitrification (partial nitrification) technology can save 25% of aeration energy consumption compared with the traditional nitrification process. The combined technology of the anaerobic ammonium oxidation technology and the anaerobic ammonium oxidation technology has the outstanding advantages of saving carbon sources, reducing sludge yield and the like, accords with the idea of establishing a sewage treatment plant with Chinese concept, and has wide application prospect. However, short-cut nitrification has the problem of difficult long-term stable operation in town wastewater with low ammonia nitrogen concentration, which seriously limits the application of short-cut nitrification technology in town sewage treatment.

Zeolite is used as an ammonia nitrogen selective adsorbent, and free ammonia is released after adsorption saturation to inhibit the activity and growth of nitrosomonas, so that the zeolite is widely applied to the field of short-cut nitrification process control. However, the traditional zeolite biofilm reactor has the defects of tight filling of fillers, poor mass transfer and the like, so that the activity of the later-stage ammonia oxidation sludge is reduced, the performance of the reactor is deteriorated, and the long-term stable short-cut nitrification process is difficult to realize. In addition, the effluent quality of the traditional short-cut nitrification process is mainly realized through manual monitoring, the defects that the physicochemical indexes in the reactor cannot be monitored in time and the operation program of the reactor is changed correspondingly exist, and the stable operation of the short-cut nitrification is also greatly restricted. Meanwhile, the conventional short-cut nitrification sequencing batch process always keeps aerobic reaction in the aeration reaction stage, and ammonia oxidizing bacteria have higher oxygen affinity than nitroso-nitrogen bacteria, so that the aerobic reaction is always kept, the activity of the nitroso-nitrogen bacteria is not favorably inhibited, and the establishment of short-cut nitrification is also influenced.

Disclosure of Invention

The invention aims to provide a process for realizing stable shortcut nitrification of town wastewater, which is specifically characterized in that zeolite-immobilized biofilm-activated sludge (IFAS) technology is utilized to treat ammonia nitrogen wastewater, and an online monitoring technology and a Sequencing Batch Reactor (SBR) method are combined to establish the stable shortcut nitrification process.

Preferably, at the beginning stage of wastewater treatment, the sodium zeolite is added into a cantilever type filler tank, the filler tank and an online monitoring probe are fixed, and simultaneously the nitrified sludge is added into the reactor, so that the sequencing batch IFAS reactor is constructed.

Preferably, the bottom and the outer wall of the cantilever type packing groove are both in a grid shape.

Further preferably, the distance between the grid and the grid is 0.5-2 mm.

Preferably, the cantilever type filler groove is fixed in a clamping groove of the wall of the reactor.

Preferably, 4-10 cantilever type packing grooves can be fixed on the wall of the reactor at the same height.

Preferably, the particle size of the sodium type zeolite is more than or equal to 3 mm.

More preferably, the particle size of the sodium-type zeolite is 3-5 mm.

Preferably, the online monitoring probe comprises: ammonia nitrogen/nitrate nitrogen, DO (dissolved oxygen), pH, ORP (oxidation reduction potential).

Further preferably, the online monitoring probe is fixed at the position 1/3-1/2 of the height of the reactor.

Preferably, the nitrified sludge is activated sludge in an aerobic tank of a municipal sewage treatment plant.

Further preferably, the inoculation concentration of the activated sludge is 3000-4000 mg/L.

Preferably, the aeration reaction procedure of the Sequencing Batch Reactor (SBR) adopts an intermittent aeration mode, and comprises a micro-aerobic section and an anaerobic section.

Further preferably, the time ratio of the micro-aerobic section to the anaerobic section is 4: 1.

further preferably, the DO of the micro-aerobic section is 0.7-0.9 mg/L, and the DO of the anaerobic section is 0.1-0.3 mg/L.

Preferably, the ammonia nitrogen concentration of the town wastewater is 30-50 mg/L.

Further preferably, the ammonia nitrogen concentration of the town wastewater is 45-50 mg/L.

Preferably, the method of the present invention comprises the steps of:

in the initial stage of wastewater treatment, adding sodium zeolite into a cantilever type filler tank, fixing the filler tank and an online monitoring probe, and simultaneously adding nitrified sludge into a reactor to construct a sequencing batch IFAS reactor; the bottom and the outer wall of the cantilever type packing groove are both in a grid shape, the distance between the grid and the grid is 0.5mm, the cantilever type packing groove is fixed on the wall of the reactor, and 8 packing grooves can be fixed on the wall of the reactor at the same height; the online monitoring probe is fixed at 1/3-1/2 of the height of the reactor; the nitrified sludge is activated sludge in an aerobic tank of a municipal sewage treatment plant; the aeration reaction procedure of the sequencing batch activated sludge process adopts an intermittent aeration mode; the aeration device comprises two aeration stages of a micro-oxygen section and an anaerobic section, wherein the time ratio of the micro-oxygen section to the anaerobic section is 4: 1; the ammonia nitrogen concentration of the town wastewater is 45-50 mg/L.

The method has the following beneficial effects:

1) the fixed carrier of sodium zeolite filler tank as the biomembrane that this application adopted, alternative adsorption ammonium radical ion, and it is very big to adsorb the saturation capacity, can release free ammonia in a large number after reaching adsorption balance, form the high free ammonia environment in the microenvironment, and the inhibitory concentration that ammonia oxidizing bacteria received free ammonia is far above the nitrosonium oxidation bacterium, therefore the zeolite carrier not only is favorable to promoting ammonia oxidizing bacteria (AOB)'s activity and growth, can restrain the activity and the growth of Nitrosonium Oxidation Bacterium (NOB) moreover.

2) The grid-shaped packing groove adopted by the application not only increases the specific surface area of the seasoning layer, is favorable for the formation of sludge attached to a biological membrane, but also increases the mass transfer effect, and avoids the influence on the shortcut nitrification effect caused by the decrease of the permeability of the matrix in the later period.

3) The online monitoring technology adopted by the application is beneficial to monitoring the ammonia nitrogen concentration, the nitrate nitrogen concentration, the DO (dissolved oxygen) concentration, the pH and the ORP (oxidation-reduction potential) in the sewage of the reactor in time, so as to help to know whether the performance and the program of the reactor are reasonable or not in time and conveniently regulate and control the operation program of the reactor in time.

4) The DO concentration in the reactor can be effectively controlled by the intermittent aeration reaction procedure, the reactor is always in a micro-aerobic or anaerobic state, and the oxygen affinity of ammonia oxidizing bacteria is far higher than that of nitrosobacteria, so that the activity and growth of the nitrosobacteria can be effectively inhibited by the aeration mode.

Drawings

FIG. 1 is a schematic front view of a structure of a fixed biofilm-activated sludge sequencing batch process prepared in example 1 of the present invention;

FIG. 2 is a schematic top view showing the structure of a fixed biofilm-activated sludge sequencing batch process prepared in comparative example 1 according to the present invention;

fig. 3 is a schematic view of the slot wall or slot bottom of the cantilever-type filler slot prepared in example 1 of the present invention.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

Example 1

Step 1:

the design of the fixed biological membrane-activated sludge sequencing batch reactor comprises the following components (refer to the attached figure 1): a fixed biomembrane-activated sludge sequencing batch reactor for realizing stable short-cut nitrification of town wastewater comprises a reactor cylinder 4, a water bath jacket 5, a water inlet 1 and a water outlet 8 of the water bath jacket. A packing groove 3 and an online monitoring probe 6 are fixed in the reactor, and the wall of the reactor is connected with a water inlet 2 and a water outlet 7, wherein the diameter of the reactor cylinder body is 1m, the height of the reactor cylinder body is 1.2m, and the thickness of a jacket is 8 cm.

Step 2:

the method for detecting the concentration of the free ammonia in the microenvironment of the packing groove in the embodiment and determining the process effect comprises the following steps:

1) manufacturing and building the fixed biological membrane-activated sludge sequencing batch reactor designed in the step 1, adding wastewater to be treated, wherein the initial concentration of ammonia nitrogen in the wastewater is 50mg/L, and setting the HRT of SBR to be 8 h.

2) After 3 days, the packing box was taken out and the ammonium ion and hydrogen ion concentrations at 5 μm, 10 μm, 50 μm, 100 μm, 500 μm, 1mm and 1cm from the zeolite packing box were measured in situ using non-destructive microassay technique to calculate the Free Ammonia (FA) concentration at each distance point as follows:

according to the test and calculation results, the FA concentration is higher than 0.1mg/L within the range of 1cm around the filler groove, and the FA inhibition concentration of AOB and NOB is respectively 10mg/L and 0.1mg/L, so that FA released by the zeolite filler has an inhibition effect on the activity of NOB, and has an promotion effect on the activity of AOB, and therefore, the process has an ammonia-releasing nitrate-inhibiting effect.

And step 3:

the operation of treating the wastewater containing ammonia nitrogen by using the device and the method of the embodiment comprises the following steps:

inoculating activated sludge in an aerobic pool of a sewage treatment plant in the reactor established in the step 2 to ensure that the sludge concentration is 3000-4000 mg/L, the DO in a micro-aerobic aeration stage is kept at 0.7-0.9 mg/L, the DO in an anaerobic aeration stage is kept at 0.1-0.3, continuously running for 30 days, counting the ammonia nitrogen and nitrate nitrogen concentration of inlet and outlet water in each period, and manually detecting the nitrite nitrogen concentration of inlet and outlet water in each period;

obvious nitrite nitrogen accumulation appears in the reactor from the 3 rd day after inoculation, the ammonia nitrogen concentration of effluent is 24.6mg/L at the 30 th day, and the ammonia oxidation rate is 51.2%; the concentration of nitrate nitrogen is 3.6mg/L, the concentration of nitrite nitrogen is 20.6mg/L, the accumulation rate of nitrite nitrogen reaches 85.1 percent, and the requirement of the short-cut nitrification process is met.

Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims

1. A process for realizing stable shortcut nitrification of town wastewater is characterized in that the town wastewater is treated by utilizing a fixed biomembrane-activated sludge technology, and an online monitoring technology and a sequencing batch activated sludge process are combined at the same time; the reactor comprises a reactor barrel (4), a water bath jacket (5), a water inlet and a water outlet of the water bath jacket, wherein a cantilever type fixed filler groove (3) and an online monitoring probe (6) are arranged in the reactor, the cantilever type fixed filler groove (3) is arranged in a clamping groove in the inner wall of the reactor, the wall of the reactor is connected with the water inlet and the water outlet of town wastewater, the bottom and the outer wall of the cantilever type fixed filler groove (3) are in a grid shape, and the distance between the grid and the grid is 0.5-2 mm; at the beginning stage of wastewater treatment, sodium zeolite is added into the cantilever type fixed filler groove, the cantilever type fixed filler groove and the online monitoring probe are fixed, meanwhile, nitrified sludge is added into the reactor, and a sequencing batch fixed biological membrane-activated sludge reactor is constructed.

2. The process of claim 1, wherein 4 to 10 of said cantilevered fixed packing slots are fixed to said reactor wall at the same height of the reactor inner wall.

3. The process as claimed in claim 1, wherein the sodium zeolite has a particle size of 3mm or more.

4. The process of claim 1, wherein the on-line monitoring probe is fixed at 1/3-1/2 of the height in the reactor.

5. The process according to any one of claims 1 to 4, wherein the nitrified sludge is activated sludge from an aerobic tank of a municipal sewage treatment plant.

6. The process as claimed in any one of claims 1 to 4, wherein the aeration reaction procedure of the sequencing batch activated sludge process adopts an intermittent aeration mode, and comprises a micro-aerobic section and an anaerobic section, and the aeration time ratio of the micro-aerobic section to the anaerobic section is 4: 1.

7. The process according to any one of claims 1 to 4, wherein the initial content of ammonia nitrogen in the wastewater is 30 to 50 mg/L.