CN109851168B

CN109851168B - A2Improvement of/O process

Info

Publication number: CN109851168B
Application number: CN201910108354.0A
Authority: CN
Inventors: 张建中; 梁爽
Original assignee: Environmental Protection Institute of Light Industry
Current assignee: Environmental Protection Institute of Light Industry
Priority date: 2019-02-13
Filing date: 2019-02-13
Publication date: 2022-02-08
Anticipated expiration: 2039-02-13
Also published as: CN109851168A

Abstract

The invention discloses a²The improvement of the/O process comprises an anaerobic tank, an anoxic tank, an aerobic tank, a secondary sedimentation tank, a backflushing tank, a middle sedimentation tank, an ammonia absorption tank, a steady flow tank, a nitre sedimentation tank, a nitrification tank and a buffer tank; the ammonia absorption tank has more than two grids, and each grid is independent; the adsorption effect of zeolite on ammonia nitrogen is utilized to adsorb the ammonia nitrogen in the sewage, and the zeolite is nitrified and regenerated independently, so that the nitrifying process is carried out independently, carbon source loss is avoided, the utilization efficiency of a carbon source is improved, and meanwhile, the denitrification rate which is difficult to improve due to the limitation of reflux ratio is avoided, and the denitrification rate is improved.

Description

A2Improvement of/O process

Technical Field

The invention relates to a sewage treatment system, in particular to a sewage treatment system A²The process is carried out by adopting a/O technology.

Background

A²the/O process is a classical process for sewage treatment, and the process flow is shown in figure 2 of the attached drawing of the specification. The process has many advantages, but also has disadvantages. The most important defects are three points: firstly, both denitrification and dephosphorization cannot be optimized simultaneously; firstly, the removal rate of denitrification is difficult to be greatly improved, and firstly, the carbon source is tense.

For this purpose, the technician pairs A²the/O process is improved greatly and has pre-denitration A²O, inversion A²The processes of/O, UCT, Phoredox and the like.

The zeolite of this patent adsorbs ammonia nitrogen characteristic, to A²An improvement was also made in the/O process.

Disclosure of Invention

The invention aims to provide a²The improvement of the/O process is characterized in that: the device consists of an anaerobic tank, an anoxic tank, an aerobic tank, a secondary sedimentation tank, a back flushing tank, a middle sedimentation tank, an ammonia absorption tank, a steady flow tank, a nitre sedimentation tank, a nitrification tank and a buffer tank; the ammonia absorption tank has more than two grids, and each grid is independent; the sewage is operated according to the following steps:

step one, sewage enters an anaerobic tank to carry out a corresponding biochemical process; after reaction, the mixed liquid in the anaerobic tank enters an anoxic tank to carry out corresponding biochemical process; after reaction, the mixture in the anoxic tank enters a middle sedimentation tank for solid-liquid separation;

step two, the water separated from the intermediate sedimentation tank enters a grid in an ammonia absorption tank; the mud separated from the intermediate sedimentation tank enters an aerobic tank;

step three, zeolite is arranged in the ammonia absorption tank, water entering the ammonia absorption tank is subjected to ammonia nitrogen adsorption by the zeolite and then enters the aerobic tank;

monitoring the content of the ammonia nitrogen in the effluent water of the water inlet grid of the ammonia absorption tank, stopping water inflow to the grid when the content reaches a set value (namely, when the adsorption is saturated), and turning to water inflow of another grid so as to keep the continuity of water inflow; pumping the water in the steady flow tank into a grid with saturated adsorption in an ammonia absorption tank, displacing the water in the steady flow tank, introducing the displaced water into a nitrification tank for nitrification reaction, performing solid-liquid separation on nitrified mixed liquid in a nitre settling tank, refluxing mud, introducing the water into the steady flow tank, pumping the water into the ammonia absorption tank again to form circulation, and stopping the circulation until the regeneration of zeolite in the ammonia absorption tank is finished; then pumping the water in the backflushing pool into the grid of the ammonia absorption pool, displacing and washing the water containing the nitrate in the water, and entering a buffer pool; the nitrate-containing water in the buffer tank enters an anoxic tank to carry out a corresponding biochemical process; the regenerated, replaced and washed lattice is kept stand for standby;

the ammonia absorption tank has more than two grids, and the circulation process of ammonia absorption, regeneration, replacement, washing, standby and ammonia re-absorption is carried out for each grid in turn, so that the result of continuously treating the sewage is achieved;

and step five, after the water subjected to ammonia absorption in the step three enters an aerobic tank, carrying out aerobic reaction in the aerobic tank together with the sludge separated from the intermediate sedimentation tank, allowing the mixed liquid to enter a secondary sedimentation tank for solid-liquid separation, overflowing and discharging the separated water through a backflushing tank, returning one part of the separated sludge to the anaerobic tank, and discharging the other part of the separated sludge serving as residual sludge out of the system.

Compared with the prior treatment process, A²The beneficial effects of the improvement of the/O process are as follows: the nitrification process is independently carried out, so that the carbon source loss is avoided, the utilization efficiency of the carbon source is improved, and meanwhile, the denitrification rate which is difficult to improve due to the limitation of the reflux ratio is avoided, so that the denitrification rate is improved.

Drawings

FIG. 1 is a schematic process flow diagram of an embodiment of the present invention. FIG. 2 is classic A²Schematic flow diagram of the/O process.

Detailed Description

Example (b):

in the embodiment, the device consists of an anaerobic tank 1, an anoxic tank 2, an aerobic tank 3, a secondary sedimentation tank 4, a backflushing tank 5, a middle sedimentation tank 6, an ammonia absorption tank 7, a steady flow tank 8, a nitre sedimentation tank 9, a nitrification tank 10 and a buffer tank 11; the ammonia absorption tank 7 has more than two grids, and each grid is independent; the sewage is operated according to the following steps:

step one, sewage enters an anaerobic tank 1 to carry out a corresponding biochemical process; in the anaerobic tank 1, the anaerobic phosphorus release reaction is mainly carried out, and the sludge returned by the secondary sedimentation tank 4 is ready for aerobic phosphorus absorption after the phosphorus release. After reaction, the mixed liquid in the anaerobic tank 1 enters the anoxic tank 2 to carry out corresponding biochemical process; in the anoxic pond 2, denitrification is mainly carried out, nitrate nitrogen coming from the buffer pond is reduced to N by using an organic carbon source under the action of denitrifying bacteria₂. After reaction, the mixture in the anoxic tank enters a middle sedimentation tank 6 for solid-liquid separation;

step two, the water separated from the intermediate sedimentation tank 6 enters a grid in an ammonia absorption tank 7; mud separated from the intermediate sedimentation tank 6 enters an aerobic tank 3;

step three, zeolite is arranged in the ammonia absorption tank 7, and the zeolite has a specific adsorption effect on ammonia nitrogen, so that the ammonia nitrogen in the water entering the ammonia absorption tank 7 is adsorbed by the zeolite, and the separation of the ammonia nitrogen and the sewage is realized; separating the ammonia nitrogen from the sewage, and feeding the sewage into an aerobic tank 3;

monitoring the content of the ammonia nitrogen in the outlet water of the water inlet grid of the ammonia absorption pool 7, stopping water inlet to the grid when the content reaches a set value (namely, when the adsorption is saturated), and turning to water inlet of another grid so as to keep the continuity of water inlet; pumping water in the steady flow tank 8 into a lattice which is saturated in adsorption in the ammonia absorption tank 7, displacing the water in the steady flow tank, allowing the displaced water to enter a nitrification tank 10 for nitrification reaction, performing solid-liquid separation on nitrified mixed liquid in a nitre sedimentation tank 9, refluxing mud, allowing the water to enter the steady flow tank 8, pumping the water into the ammonia absorption tank 7 again to form circulation, and stopping the circulation until the regeneration of zeolite in the ammonia absorption tank 7 is completed; then, pumping the water in the backflushing pool 5 into the grid of the ammonia absorption pool 7, displacing and washing the water containing the nitrate therein, and entering the buffer pool 11; the nitrate water in the buffer tank 11 enters the anoxic tank 2 to carry out the denitrification process; the regenerated, replaced and washed lattice is kept stand for standby;

adsorption of ammonia nitrogen by zeolite is an ion exchange reaction with the following equilibrium:

the adsorption process, the reaction proceeds to the right. After adsorption saturation, when water in the steady flow tank 8 is introduced into the ammonia absorption tank 7, the water in the steady flow tank 8 comes from the nitrification tank 10, so that the water in the steady flow tank 8 does not contain NH₄ ⁺Thus, NH in the ammonia suction well 7₄ ⁺The concentration will decrease and the reaction proceeds to the left, i.e. NH in the zeolite₄ ⁺And (4) desorbing. Desorbed NH₄ ⁺After entering the nitrification tank, is oxidized into NO₂ ^-Or NO₃ ^-Thus, NH in the water during the continuous circulation₄ ⁺Decrease of NH in zeolite₄ ⁺Desorption is continued and thus the zeolite is regenerated. After the zeolite is regenerated, the water in the ammonia absorption pool 7 is changed into water containing nitre, therefore, the water in the backflushing pool 5 is designed to be replaced and washed to enter the buffer pool 11, so that the ammonia absorption pool 7 does not contain ammonia and nitre, reaches the original state and is ready for next ammonia absorption.

and step five, after the water subjected to ammonia absorption in the step three enters the aerobic tank 3, carrying out aerobic reaction in the aerobic tank 3 together with sludge separated from the intermediate sedimentation tank 6, allowing the mixed liquid to enter the secondary sedimentation tank 4 for solid-liquid separation, overflowing and discharging the separated water through the backflushing tank 5, returning one part of the separated sludge to the anaerobic tank 1, and discharging the other part of the separated sludge serving as residual sludge out of the system.

The above embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and the scope of the present invention is defined by the claims. Various modifications and equivalents may be made by those skilled in the art within the spirit and scope of the present invention, and such modifications and equivalents should also be considered as falling within the scope of the present invention.

Claims

1. A²The improvement of the/O process is characterized in that: the device consists of an anaerobic tank, an anoxic tank, an aerobic tank, a secondary sedimentation tank, a back flushing tank, a middle sedimentation tank, an ammonia absorption tank, a steady flow tank, a nitre sedimentation tank, a nitrification tank and a buffer tank; the ammonia absorption tank has more than two grids, and each grid is independent; the sewage is operated according to the following steps:

monitoring the ammonia nitrogen content of the effluent of the water inlet grid of the ammonia absorption tank, stopping water inlet to the grid when the ammonia nitrogen content reaches a set value, and switching to water inlet of another grid to keep the continuity of water inlet; pumping the water in the steady flow tank into a grid with saturated adsorption in an ammonia absorption tank, displacing the water in the steady flow tank, introducing the displaced water into a nitrification tank for nitrification reaction, performing solid-liquid separation on nitrified mixed liquid in a nitre settling tank, refluxing mud, introducing the water into the steady flow tank, pumping the water into the ammonia absorption tank again to form circulation, and stopping the circulation until the regeneration of zeolite in the ammonia absorption tank is finished; then pumping the water in the backflushing pool into the grid of the ammonia absorption pool, displacing and washing the water containing the nitrate in the water, and entering a buffer pool; the nitrate-containing water in the buffer tank enters an anoxic tank to carry out a corresponding biochemical process; the regenerated, replaced and washed lattice is kept stand for standby;