CN1312270C - Method for activating and enriching nitrite bacterium - Google Patents

Abstract

The present invention relates to a method for activating and enriching nitrite bacteria, which belongs to the technology of environmental protection and provides a method for stably nitrosifying waste water. Aerobic activated sludge is used as bacterium cultures, ammonia nitrogen waste water is used as culture solution, and double-charge copper ions (Cu<2+>) with a finite concentration are continuously put into a reaction device. Simultaneously, micro organisms are cultured under an aerobic condition, the nitrosification activity of a micro organism system is gradually increased, and nitrite bacteria in the activated sludge are enriched continuously. In this way, nitrosifying reaction can be realized. The method can effectively and rapidly enrich nitrite bacteria in activated sludge particularly for waste water which has low ammonia nitrogen concentration and can not stably inhibit nitrate bacteria.

Description

Method for activating and enriching nitrite bacteria

Technical Field

The invention relates to the technical field of environmental protection, in particular to a method for activating and enriching nitrite bacteria to accumulate nitrite in waste water.

Background

Nitrosation type denitrification is a novel biological denitrification technology and is characterized in that ammonia Nitrogen (NH) in wastewater is treated under aerobic condition₄Oxidation of-N) to nitrite Nitrogen (NO)₂N), i.e. the nitration process proceeds only to the nitrosation stage.

The traditional biological aerobic nitrification comprises two steps of nitrosation and complete nitrification, and ammonia nitrogen is converted into nitrate nitrogen. The reaction formula is as follows:

from the above formula, lmgNH₄ ⁺Complete nitration of N, consumption of 4.57mg of oxygen and 7.14mg of base (as CaCO)₃Meter).

Compared with the traditional complete nitration technology, the nitrosation technology has the following advantages:

(1) the nitration reaction is only carried out to the nitrosation stage, so that the aeration energy consumption is reduced. lmgNH₄ ⁺And the nitrosation of N consumes only 3.43mg of oxygen, thereby saving the energy consumption by 25 percent.

(2) Compared with the conventional complete nitrification-denitrification process, the nitrosation is combined with the subsequent denitrification, and the organic carbon source is saved by about 40 percent.

Numerous studies have demonstrated that the key to the normal performance of the nitrosative denitrification process is to maintain the reaction of formula (1) above while inhibiting the reaction of formula (2). Therefore, accelerating the enrichment and rapid growth of nitrite bacteria and making the nitrite bacteria predominate are key technical problems to be solved. The current commonly used method for inhibiting nitrate bacteria and accumulating nitrite in waste water has the followingmain problems:

(1) the long-term stable nitrosation of the reactor cannot be guaranteed due to the gradual adaptability of the nitrate bacteria to the inhibition factors such as free ammonia.

(2) The operation control measures are complicated.

Disclosure of Invention

The invention aims to provide a method for effectively activating and culturing nitrite bacteria by utilizing the principle that the process of oxidizing ammonia nitrogen by nitrite bacteria is a metalloenzyme-catalyzed biological reaction, and overcomes the defects of the conventional nitrosation method.

In order to achieve the aim, the technical scheme of the invention is to provide a method for activating and enriching nitrite bacteria, aerobic activated sludge is used as a strain, ammonia nitrogen wastewater is used as a culture solution, and divalent copper ions (Cu) with certain concentration are continuously added into a reaction device²⁺) Meanwhile, microorganisms are cultured under an aerobic condition, the nitrosation activity of a microorganism system is gradually enhanced, nitrite bacteria in the activated sludge are continuously enriched, and the nitrosation reaction can be realized;

divalent copper ion (Cu)²⁺) The amount of (A) is such that divalent copper ions (Cu) in the slurry-water mixture of the reaction apparatus²⁺) Concentration of (2)The concentration of the active component is 0.5-1.5 mg/L.

The method, one reaction cycle of which comprises the following steps:

a) putting the seed sludge into a reaction device;

b) the reaction device is fed with a solution containing a certain concentration of divalent copper ions (Cu)²⁺) The domestic sewage of (1) is treated,

forming a mud-water mixed solution;

c) carrying out aeration and aerobic culture;

d) after the aeration reaction is finished, the mud-water mixed liquid is statically precipitated;

e) the supernatant was drained.

In the method, the sludge concentration of the sludge-water mixed solution in the reaction device is 2000-3000 mg/L (MLSS).

The method of the invention has the following advantages:

(1) the microbial culture period is short, the time is saved, and the reaction device can ensure long-term stable nitrosation.

(2) The operation method is simple and the operation is simple and convenient.

(3) Particularly for wastewater which is low in ammonia nitrogen concentration and cannot stably inhibit the formation of nitrate bacteria, the method can effectively and quickly enrich nitrite bacteria in the activated sludge, and realize nitrosation.

Drawings

FIG. 1 is a schematic view of a reaction apparatus used in the method of the present invention.

Detailed Description

The reaction device adopted by the method of the invention is shown in the attached figure 1. The reaction device 1 is a closed body, a water inlet pipe 5 and a liquid level control device 8 are arranged at the upper part in the cavity of the reaction device 1, and the liquid level control device8 is positioned below the water inlet pipe 5; the bottom is provided with an air inlet pipe 6, and the inner end of the air inlet pipe 6 is fixedly connected with an aeration head 2. And a drain pipe 7 is arranged on the side wall below the liquid level control device 8, and a drain valve 4 is arranged in a channel of the drain pipe 7.

The reaction device 1 adopts an SBR operation mode, namely four steps of water inlet, aeration, sedimentation and water drainage are completed in one device. Seed sludge (aerobic activated sludge) is fed into a reaction apparatus 1 and contains certain divalent copper ions (Cu)²⁺) The waste water of concentration gets into reaction unit 1 from upper portion inlet tube 5, reaches the control liquid level after, closes inlet tube 5 by liquid level control device 8, stops intaking, and waste water and seed mud intensive mixing in muddy water mixed liquid reaction zone 3, and the rethread intake pipe 6 gives gas through aeration head 2, carries out biological aerobic reaction, and after the aeration reaction, muddy water mixed liquid is quiet heavy, then opens drain valve 4, discharges the supernatant by drain pipe 7. The next reaction cycle is then carried out. The amount of the seed sludge added enables the sludge concentration of the mixed liquid in the reaction device 1 to reach: MLSS is 2000-3000 mg/L; divalent copper ion (Cu)²⁺) The amount of (A) is such that divalent copper ions (Cu) in the slurry-water mixture of the reaction apparatus²⁺) The concentration of (A) is 0.5-1.5 mg/L. The conditions of ammonia nitrogen load, dissolved oxygen, temperature, pH and the like do not need to be controlled in the reaction process.

Example 1:

a reaction apparatus 1 shown in FIG. 1 was used.

Aerobic activated sludge for treating domestic sewage is taken as a strain, and bivalent copper ions (Cu) with certain concentration are introduced²⁺) The domestic sewage has a sludge concentration of 2600mg/L and divalent copper ions (Cu)²⁺) The concentration of (B) was about 1mg/L, and aerobic culture was carried out, and the culture results are shown in the following table. As can be seen from the results, by adding divalent copper ions (Cu)²⁺) The proportion of nitrite bacteria in the activated sludge is continuously increased, the nitrosation rate is gradually increased, and nitrite bacteria are enriched; meanwhile, the degradation capability of the microorganism on organic matters (CODcr) is not influenced.

Claims (3)

1. A method for activating and enriching nitrite bacteria is characterized in that: using aerobic activated sludge as a strain, using ammonia nitrogen wastewater as a culture solution, and continuously adding divalent copper ions (Cu) into a reaction device²⁺) Meanwhile, microorganisms are cultured under an aerobic condition, the nitrosation activity of a microorganism system is gradually enhanced, nitrite bacteria in the activated sludge are continuously enriched, and the nitrosation reaction can be realized;

divalent copper ion (Cu)²⁺) The amount of (A) is such that divalent copper ions (Cu) in the slurry-water mixture of the reaction apparatus²⁺) The concentration of (A) is 0.5-1.5 mg/L.

2. The method of claim 1, wherein: one reaction cycle comprises the following steps:

a) putting the seed sludge into a reaction device;

b) the reaction apparatus is fed with a solution containing divalent copper ions (Cu)²⁺) The domestic sewage of (1) to form muddy water

Mixing the solution;

c) carrying out aeration and aerobic culture;

d) after the aeration reaction is finished, the mud-water mixed liquid is statically precipitated;

e) the supernatant was drained.

3. The method of claim 2, wherein: the sludge concentration of the sludge-water mixed liquid in the reaction device is 2000-3000 mg/L (MLSS).