CN212894108U

CN212894108U - System for handle high COD high ammonia nitrogen waste water

Info

Publication number: CN212894108U
Application number: CN202021812532.2U
Authority: CN
Inventors: 李丽; 韩昫身; 狄磊; 金艳; 李峰; 陈胤晖; 徐曙华; 祁嘉炜
Original assignee: Suzhou Daoyuan Huazhi Environmental Protection Technology Co ltd
Current assignee: Suzhou Daoyuan Huazhi Environmental Protection Technology Co ltd
Priority date: 2020-08-26
Filing date: 2020-08-26
Publication date: 2021-04-06
Anticipated expiration: 2030-08-26

Abstract

The utility model discloses a system for handle high COD high ammonia nitrogen waste water, it includes several parts of leading oxygen deficiency pond, leading good oxygen pond, rearmounted oxygen deficiency pond and rearmounted membrane bioreactor. The system for treating the high-COD high-ammonia nitrogen wastewater has the characteristics of simple composition, flexible operation, strong impact resistance, good reliability and the like; compared with the traditional first-stage A/O process, the process combined with the membrane bioreactor can effectively degrade residual organic matters and total nitrogen in the first-stage A/O produced water, and improve the removal efficiency of the pollutants in the whole process, wherein the removal rate of COD is 90-95%, the removal rate of ammonia nitrogen is 95-98%, and the removal rate of total nitrogen is 95-97%; compared with a two-stage A/O process, the process adopts an immersed ultrafiltration membrane separation to replace an original continuous flow secondary sedimentation tank with larger occupied area, improves the sludge concentration, improves the effluent quality and saves the occupied area.

Description

System for handle high COD high ammonia nitrogen waste water

Technical Field

The utility model relates to a waste water treatment process, in particular to a system and a process for treating high COD high ammonia nitrogen waste water by adopting a two-stage AO waste water treatment process.

Background

In the field of water treatment, the municipal sewage system with low ammonia nitrogen and organic matter content is treated by adopting the conventional A/O process at present. AO process is also called anaerobic aerobic process, A (Anaerobic) is anaerobic section, used for removing nitrogen and phosphorus; o (oxic) is an aerobic section for removing organic matter from water. Its advantages are degradation of organic pollutant, and certain function of removing nitrogen and phosphorus. The traditional A/O process is formed by connecting an anoxic tank and an aerobic tank in series, can remove organic matters and simultaneously reduce total nitrogen, and is characterized in that wastewater enters the anoxic tank, denitrifying bacteria take the organic matters in the wastewater as a carbon source and nitrate in return sludge as a nitrogen source to perform denitrification reaction so as to realize denitrification. Then the sewage enters an aerobic tank, sufficient nitrate is generated by nitration reaction, and a sedimentation tank is arranged at the rear end of the aerobic tank.

The method has the advantages of simple process and low operation cost, but has certain requirements on the ratio of BOD 5/TKN in the sewage, and when the operation working condition is not good, the sludge in the sedimentation tank is easy to float. Particularly, the conventional treatment method has limitation on the wastewater containing high-concentration ammonia nitrogen, and the effluent is difficult to discharge after reaching the standard. In order to improve the degradation efficiency of organic matters and total nitrogen, the reflux ratio must be increased, the operation cost is greatly increased, the section A is difficult to maintain an ideal anoxic state, and the quality of produced water does not reach the standard. Along with the improvement of environmental protection standard, the high ammonia nitrogen high organic matter waste water that some enterprises produced is waited for immediately to treat the back and is discharged up to standard, improves the waste water treatment effect through reforming transform traditional technology and is the research focus of present stage.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects in the prior art, the utility model aims to provide a wastewater treatment system and a process for improving the removal efficiency of organic matters and ammonia nitrogen in a high ammonia nitrogen and high organic matter system.

A system for treating high COD high ammonia nitrogen wastewater comprises: the pre-anoxic tank is connected with a wastewater inlet and is used for preliminarily degrading organic matters and removing nitrified nitrogen; the water inlet of the preposed aerobic tank is connected with the water outlet of the preposed anoxic tank, the preposed aerobic tank is also connected with the preposed anoxic tank through a liquid outlet, and the preposed aerobic tank is used for carrying out nitration treatment on wastewater; the water inlet of the rear anoxic tank is connected with the water outlet of the front aerobic tank, and the rear anoxic tank is used for carrying out denitrification treatment on the nitrate nitrogen remained in the aerobic tank; the membrane bioreactor comprises a rear membrane bioreactor, wherein a water inlet of the rear membrane bioreactor is connected with a water outlet of a rear anoxic tank, the rear membrane bioreactor is further provided with a sludge backflow port, the sludge backflow port is connected with the front anoxic tank, the rear membrane bioreactor is used for removing residual organic matters and ammonia nitrogen in wastewater, and meanwhile, solid-liquid separation is carried out, so that the occupied area is reduced, and higher sludge concentration is kept.

Preferably, the post-membrane bioreactor is provided with an immersed ultrafiltration membrane.

The technical scheme has the following beneficial effects: the system for treating the high-COD high-ammonia nitrogen wastewater has the characteristics of simple composition, flexible operation, strong impact resistance, good reliability and the like; compared with the traditional first-level A/O process, the process combined with the membrane bioreactor can effectively degrade residual organic matters and ammonia nitrogen in the first-level A/O produced water, and improve the removal efficiency of pollutants in the whole process, wherein the removal rate of COD is 90-95%, the removal rate of ammonia nitrogen is 95-98%, and the removal rate of total nitrogen is 95-97%; compared with a two-stage A/O process, the process adopts an immersed ultrafiltration membrane separation to replace an original continuous flow secondary sedimentation tank with larger occupied area, improves the sludge concentration, improves the effluent quality and saves the occupied area.

Drawings

Fig. 1 is a system block diagram of an embodiment of the present invention.

Detailed Description

The following description is provided for illustrative purposes, and other advantages and features of the present invention will become apparent to those skilled in the art from the following detailed description.

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, devices, steps, and so forth. In other instances, well-known technical solutions have not been shown or described in detail to avoid obscuring aspects of the present invention.

As shown in figure 1, the patent discloses a system for treating high COD high ammonia nitrogen wastewater, which comprises a preposed anoxic tank 1, a preposed aerobic tank 2, a postposed anoxic tank 3 and a postposed membrane bioreactor 4. Leading oxygen deficiency pond 1 is connected with the waste water inlet, the water inlet of leading good oxygen pond 2 is connected with the delivery port of leading oxygen deficiency pond 1, leading good oxygen pond 2 still is connected with leading oxygen deficiency pond 1 through a liquid outlet, the water inlet of rearmounted oxygen deficiency pond 3 is connected with the delivery port of leading good oxygen pond 1, the water inlet of rearmounted membrane bioreactor 4 is connected with the delivery port of rearmounted oxygen deficiency pond 3, rearmounted membrane bioreactor 4 still is equipped with a silt backward flow mouth, the silt backward flow mouth is connected with leading oxygen deficiency pond 1.

The preposed anoxic tank 1 is used for carrying out preliminary degradation organic matter and denitrification treatment on wastewater, the preposed aerobic tank 2 is used for carrying out nitration treatment on the wastewater, the postpositional anoxic tank 3 is used for carrying out denitrification treatment on the wastewater, and the postpositional membrane bioreactor 4 deeply removes residual organic matters and ammonia nitrogen in the wastewater by adopting an activated sludge process and carries out solid-liquid separation. The mixed liquid of nitrite bacteria and nitrate bacteria in the preposed aerobic tank 2 can flow back to the preposed anoxic tank 1 through the liquid outlet, and partial sludge generated in the post-membrane bioreactor 4 can flow back to the preposed anoxic tank 1 through the sludge return port.

In order to control the OD (dissolved oxygen) in the preposed aerobic tank 2 and the postpositional membrane bioreactor 4 conveniently, aeration pipes can be arranged at the bottoms of the preposed aerobic tank 2 and the postpositional membrane bioreactor 4. Meanwhile, in order to ensure that the median of the particle size of the produced water is lower than 20 mu m, a submerged ultrafiltration membrane can be arranged in the post-membrane bioreactor 4.

The patent also discloses a process for treating high COD high ammonia nitrogen wastewater, which specifically comprises the following steps:

1) injecting the wastewater into a preposed anoxic tank, carrying out denitrification reaction by taking organic matters in the wastewater as a carbon source and taking a mixed solution of nitrite and nitrate in a preposed aerobic tank as a nitrogen source, and supplementing part of returned sludge of a postposition membrane bioreactor to preliminarily reduce the concentration of the organic matters and the total nitrogen in the wastewater. In the process, the retention time of the wastewater in the preposed anoxic tank 1 is 4-16h, DO in the preposed anoxic tank 1 is controlled to be less than or equal to 0.3mg/L, and the pH value is controlled to be 7-8.

2) After the treatment in the preposed anoxic tank is finished, the effluent of the preposed anoxic tank enters a preposed aerobic tank, ammonia nitrogen in the wastewater is converted into nitrate nitrogen by using domesticated nitrite bacteria and nitrate bacteria, and part of mixed liquid in the preposed aerobic tank flows back to the preposed anoxic tank. In the process, the waste water stays in the preposed aerobic tank for 8-20h, and an aeration pipe is arranged at the bottom to ensure that DO is more than or equal to 2 mg/L; in order to control nitrifying bacteria as dominant bacteria, the pH needs to be controlled to be 7.5-8.5, the total alkalinity is enabled to be more than 70mg/L by appropriately supplementing alkalinity, and the reflux ratio of nitrifying liquid is controlled to be 500: 1-200: 1, controlling the temperature to be 25-35 ℃; the O1 pool is filled with filler, which can ensure the adhesion of activated sludge, reduce the loss of sludge and improve the degradation efficiency.

3) Then leading the effluent of the front-mounted aerobic tank to enter a rear-mounted aerobic tank, supplementing a certain amount of carbon source, further denitrifying nitrate in the wastewater, and deeply removing total nitrogen; in the process, the retention time of the wastewater in the post-aerobic tank is controlled to be 2-12h, DO in the post-aerobic tank is less than or equal to 0.3mg/L, the alkalinity can be supplemented appropriately, the pH value is adjusted to be maintained at 7-8, and a carbon source can be supplemented appropriately to improve the denitrification efficiency, wherein the type of the carbon source comprises one or more of glucose, dextrin, starch, sodium acetate and methanol.

4) And finally, enabling the effluent of the post-aerobic tank to enter a post-membrane bioreactor, deeply removing residual organic matters and ammonia nitrogen in the wastewater by using the post-membrane bioreactor by adopting an activated sludge process, carrying out solid-liquid separation, discharging or recycling the produced water after reaching the standard, and refluxing the residual sludge to the pre-anoxic tank. An aeration pipe can be arranged at the bottom of the post-membrane bioreactor, DO is controlled to be more than or equal to 2mg/L, and an immersed ultrafiltration membrane is arranged in the post-membrane bioreactor, so that the median of the particle size of the produced water can be ensured to be lower than 20 mu m.

Example one

Coal chemical wastewater is taken as a research object, the coal chemical wastewater inlet CODcr is 1200 mg/L, the ammonia nitrogen is 350 mg/L, the total nitrogen is 400 mg/L, and the total suspended matter concentration is 300 mg/L. The coal chemical wastewater is treated by adopting the process steps, the CODcr of produced water after the system is operated is 20-50 mg/L, the ammonia nitrogen is less than or equal to 5mg/L, the total nitrogen is less than or equal to 10mg/L, and the concentration of total suspended matters is less than or equal to 5mg/L, so that the first-level discharge standard of the GB 8978-1996 integrated wastewater discharge standard can be reached.

Embodiment two

The synthetic ammonia wastewater is taken as a research object, the inflow water CODcr of the synthetic ammonia wastewater is 800 mg/L, the ammonia nitrogen is 300 mg/L, the total nitrogen is 350 mg/L, and the concentration of total suspended matters is 300 mg/L. The synthetic ammonia wastewater is treated by adopting the process steps, the CODcr of produced water after the system is operated is 20-40 mg/L, the ammonia nitrogen is less than or equal to 2mg/L, the total nitrogen is less than or equal to 10mg/L, and the concentration of total suspended matters is less than or equal to 5mg/L, so that the synthetic ammonia wastewater can reach the first-grade discharge standard of the GB 8978-1996 sewage comprehensive discharge standard.

Therefore, compared with the traditional first-level A/O process, the process combined with the membrane bioreactor can effectively degrade residual organic matters and total nitrogen in the first-level A/O water production, and improve the removal efficiency of the pollutants in the whole process, wherein the removal rate of COD is 90-95%, the removal rate of ammonia nitrogen is 95-98%, and the removal rate of total nitrogen is 95-97%; compared with a two-stage A/O process, the process adopts an immersed ultrafiltration membrane separation to replace an original continuous flow secondary sedimentation tank with larger occupied area, improves the sludge concentration, improves the effluent quality and saves the occupied area, and meanwhile, the system for treating the high-COD high-ammonia nitrogen wastewater has the characteristics of simple composition, flexible operation, strong impact resistance, good reliability and the like.

The above embodiments are merely illustrative of the principles and effects of the present invention, and are not to be construed as limiting the invention. Modifications and variations can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which may be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. The utility model provides a handle system of high COD high ammonia nitrogen waste water which characterized in that, it includes:

the pre-anoxic tank is connected with a wastewater inlet and is used for preliminarily degrading organic matters and removing nitrified nitrogen;

the water inlet of the preposed aerobic tank is connected with the water outlet of the preposed anoxic tank, the preposed aerobic tank is also connected with the preposed anoxic tank through a liquid outlet, and the preposed aerobic tank is used for carrying out nitration treatment on wastewater;

the water inlet of the rear anoxic tank is connected with the water outlet of the front aerobic tank, and the rear anoxic tank is used for carrying out denitrification treatment on the nitrate nitrogen remained in the aerobic tank;

the water inlet of the rear membrane bioreactor is connected with the water outlet of the rear anoxic tank, the rear membrane bioreactor is also provided with a sludge backflow port, the sludge backflow port is connected with the front anoxic tank, and the rear membrane bioreactor is used for removing residual organic matters and ammonia nitrogen in the wastewater, simultaneously performing solid-liquid separation and keeping higher sludge concentration;

aeration pipes are arranged at the bottoms of the front aerobic tank and the rear membrane bioreactor.

2. The system for treating high COD and ammonia nitrogen wastewater according to claim 1, wherein the submerged ultrafiltration membrane is installed in the post-membrane bioreactor.