Total nitrogen biodegradation agent

With increasingly stringent discharge standards for urban wastewater treatment plants, the requirements for ammonia nitrogen,total nitrogen, and total phosphorus in effluent have become more rigorous. However, non-compliance with these parameters remainsthe primary challenge for treatment facilities. Therefore, selecting appropriate total nitrogen removal agents and optimizing their application methods to ensure final effluent meets municipal wastewater discharge standards has emerged as the most critical task.

In order to better meet the national standards of water quality, it is necessary to study and analyze the conventional nitrogen and phosphorus removal process of sewage treatment plant A-A-O and the dosage point and control of total nitrogen biodegradation agent.

(1) A-A-0 Process Description

A-A-0 process is a common sewage treatment process, which has the function of simultaneous phosphorus removal and nitrogen removal. It can be used for secondary sewage treatment or tertiary sewage treatment. After deep treatment, it can be used as reclaimed water, and has a good effect of nitrogen removal and phosphorus removal.

(2) Introduction to phosphorus and nitrogen removal by A-A-O process

In the A-A-O process, sewage and returned sludge enter the anaerobic tank for complete mixing. After a certain period of anaerobic decomposition, part of BOD is removed, and part of nitrogen compounds are transformed into N2 and released. The polyphosphorus microorganisms in the returned sludge release phosphorus to meet the demand of bacteria for phosphorus.

Then the sewage enters the aerobic tank, where the NH3-N (ammonia nitrogen) in the water undergoes nitrification to generate nitrate. Meanwhile, the organic matter in the water is oxidized and decomposed to provide energy for phosphorus-absorbing microorganisms. The microorganisms absorb phosphorus from the water, which enters the cell tissues and accumulates in the microorganisms. After precipitation and separation, the phosphorus-rich sludge is discharged from the system.

(3) Working principle of A-A-0 process for nitrogen removal

The A-A-0 biological nitrogen and phosphorus removal process integrates traditional activated sludge technology, biological nitrification-denitrification processes, and biological phosphorus removal methods. Its operational principle involves dividing the biological tank into anaerobic, anoxic, and aerobic zones through aeration systems, propellers in anaerobic and anoxic sections, and recirculation channels. This system effectively ——removes BOD5, SS, and nitrogen/phosphorus in various forms. The activated sludge in the A-A-0 system contains microbial communities primarily composed of nitrifying bacteria, denitrifying bacteria, and polyphosphoro￾phages. In the aerobic zone, nitrifying bacteria convert ammonia nitrogen from influent and ammonia nitrogen formed by organic ammonification into nitrate nitrogen through biological nitrification. In the anoxic zone, denitrifying bacteria transform nitrate nitrogen carried by recirculation streams into nitrogen gas through biological denitrification, achieving nitrogen removal. The anaerobic zone sees polyphosphorophages release phosphorus while absorbing easily degradable organic matter like low-grade fatty acids. In the aerobic zone,polyphosphorophages over-absorb phosphorus, which is ultimately removed through excess sludge discharge.

(4) Characteristics of total nitrogen biodegradable agent and selection of dosage point

The total nitrogen biodegradation agent primarily contains abundant facultative microorganisms and domesticated total nitrogendegrading microorganisms. These nitrogen-degrading microorganisms constitute the core component of the biodegradation system,characterized by rapid reproduction, strong adaptability, and high efficiency in nitrogen removal. It is well-established that denitrification—the primary stage of nitrogen removal—is driven by denitrifying bacteria, which are facultative microorganisms.

Enhancing the growth rate and activity of both facultative and denitrifying microorganisms remains crucial. Through extensive research and biological acclimatization, our company has cultivated microorganisms with strong adaptability to total nitrogen and high denitrification efficiency. We simultaneously introduce essential nutrients required for microbial growth. By tailoring adapted microorganisms to varying pollutant concentrations in urban wastewater, we minimize adaptation periods and improve removal efficiency. Different dosing methods and application points are selected based on wastewater treatment plant configurations and operational processes, with dosages adjusted according to influent and effluent quality. Through process optimization and parameter adjustments, effective denitrification is achieved. The dosing point selection requires consideration of operational environment requirements, with the primary application being biological reaction tanks (particularly anoxic zones). The denitrification mechanism involves converting total nitrogen into nitrogen gas through microbial metabolism. Dosage and operational parameters are dynamically adjusted according to field conditions. Typically, treating 10,000 tons of water requires adding 0.09 tons of total nitrogen biodegradation agent per unit of total nitrogen to achieve complete degradation. Dosage adjustments are made based on specific processes and operating conditions.

2. Matters needing attention after dosage.

The A-A-O process combines three key functions: organic matter removal, nitrogen elimination, and phosphorus removal.

Given that its operational parameters must simultaneously meet these multifunctional requirements, selecting appropriate chemical additives presents significant challenges and uncertainties. This complexity forms the primary reason for the intricate control system in A-A-O processes. Therefore, effective process control and management are crucial. The parameters are as follows:

1. Hydrodynamic retention time: according to the different daily treatment water quantity, the hydrodynamic retention time suitable for the sewage plant should be adjusted. Generally speaking, the hydrodynamic retention time of anaerobic section is between 1-2 hours, and that of anoxic section is between 1.5-2h. The specific adjustment should be adjusted according to the actual operation condition and experience.

2. Control of organic load: A-A-0 Denitration and phosphorus removal is a flexible process, which can focus on denitration or phosphorus removal. However, if a certain denitration effect is achieved, F/M should generally be controlled at 0.1-0.18kg brick BOD5/(kg.MLss.d), and adjusted according to the actual operating process and ambient temperature.

3. The reflux ratio r is generally between 200% and 500%, depending on the TKN concentration of the inlet and the required denitration efficiency. The external reflux ratio R is generally in the range of 50% to 100%, which can be adjusted according to the actual operation process.

4. The range of dissolved oxygen: the dissolved oxygen in anaerobic section should be controlled below 0.2mg/L, the dissolved oxygen in anoxic section should be controlled below 0.5mg/L, and the dissolved oxygen in aerobic section should be controlled within 2-3mg/L, and adjusted according to the actual operation process.

III. Cost control

This can be done without exceeding the expected cost, so that the water quality can meet the national discharge standards, which requires

The staff carried out repeated measurements and controls on site. The analysis of the cost of adding drugs was based on the on-site input

The effect of water and process flow treatment is calculated to determine the daily dosage. It has been used in numerous cases with good results.

Through comparative analysis, the total nitrogen biodegradation agent of our company has significantly improved the operation effect and far lower the operation cost

With glucose and sodium acetate, methanol, long-term addition avoids the disadvantages of using glucose and sodium acetate, glucose

The reason why it is easy to cause sludge bulking and aging with sodium acetate is that the nutrient is too single, and sodium acetate belongs to industry

The industrial salt has inhibitory effect on microbial growth. The above work needs a team with rich practical experience

To complete this, our company has such a team and also has the technical research and development capability in total nitrogen biodegradation engineering.

He has practical experience in art and technology.