Sodium acetate solution 10%20%25%30%

Molecular formula: C₂H₃NaO₂

Molecular weight: 82.03

Appearance: Colorless transparent or light yellow liquid.

Properties: Odorless, slightly bitter, the solution is weakly alkaline.

Annual production capacity: 120000 tons

Liquid sodium acetate product complies with HG/T 5959-2021 standard

HGT59592021 Biochemical treatment of wastewater using carbon source sodium acetate.pdf

Specification:

Analysis of several carbon source characteristics and sodium acetate dosage in sewage treatment plants:

With the development of the economy and human attention to the ecological environment, the requirements for nitrogen, phosphorus and other emission indicators of urban sewage treatment plants have gradually increased. However, for low-carbon and high nitrogen sewage, it is necessary to improve the denitrification level of conventional denitrification processes by adding external carbon sources such as sodium acetate. However, many cities in China have low carbon and high nitrogen phosphorus water quality characteristics in their sewage. Due to the low organic matter content, conventional denitrification processes cannot meet the carbon source requirements during the anoxic nitrification stage, which hinders the denitrification process and inhibits the growth of anaerobic bacteria. This greatly affects the denitrification efficiency of sewage treatment plants by reducing the assimilation of ammonia nitrogen (NH4-N). Practice has proven that adding carbon sources is an important means for sewage treatment plants to solve problems.

Characteristics of several carbon sources:

At present, commonly used external carbon sources for low-carbon wastewater treatment in sewage treatment plants include methanol, starch, sodium acetate, etc. Methanol and sodium acetate are both easily degradable substances that do not contain nutrients (such as nitrogen and phosphorus), and do not leave any difficult to degrade intermediate products after decomposition. Starch is a polysaccharide structure that requires a long time to hydrolyze into small molecule fatty acids, and has poor solubility in water, making it difficult to completely dissolve in water, which can easily lead to residual and excessive sludge. Research has shown that when sodium acetate is used as a carbon source, its denitrification rate is much higher than that of methanol and starch. The main reason is that sodium acetate is a low molecular weight organic acid salt that is easily utilized by microorganisms, while high molecular weight sugar substances such as starch need to be converted into low molecular weight organic acids such as acetic acid, formic acid, propionic acid, and other easily degradable organic compounds before they can be utilized. Although methanol is a rapidly biodegradable organic compound, it must be converted into low molecular weight organic acids such as acetic acid in order to be utilized by microorganisms. Therefore, using sodium acetate as a carbon source is much faster than using starch or methanol for denitrification. Meanwhile, methanol, as a flammable and explosive hazardous material, poses a certain fire hazard in its dosing room when used as an external carbon source. In the event of a fire in the methanol storage tank, it can easily lead to tank rupture or sudden boiling, causing continuous fire and explosion due to liquid overflow. The crisis scope is relatively large, so the methanol dosing room has high requirements for the surrounding environment. At the same time, due to the explosive gas mixture formed by the mixing of volatile steam and air, a special design should be adopted for the safety distance within its range.

Sodium acetate itself is not a hazardous material, convenient for transportation and storage, and cheaper than methanol. Therefore, for some sewage treatment plants, due to land limitations, using sodium acetate as an external carbon source is more advantageous than methanol when an external carbon source is needed.

Calculation of Sodium Acetate Dosage:

In the anoxic denitrification stage, nitrate nitrogen (N03-N) in wastewater is reduced to gaseous nitrogen (N2) by denitrifying bacteria. Denitrification reaction is a biochemical reaction completed by heterotrophic microorganisms, which use oxygen in nitrate (NO3-N) as an electron acceptor and organic matter (carbon source) as an electron donor under extremely low dissolved oxygen concentration conditions. In the actual process, if the sewage entering the denitrification section has a BOD5: N<4: At 1 o'clock, external carbon sources should be considered, BOD5/N≥4， It can be considered that denitrification is complete. When the carbon source is insufficient, the amount of carbon source added to the system can be calculated based on the corresponding amount of nitrate nitrogen removed. The calculation formula is: carbon source dosage (Mg-L)=(4-CBOD5/CN). CN/n, where CBOD5 is the influent BOD5 concentration, Mg/L;  CN is the nitrate concentration in the influent, and mg/Ln is the BOD5 equivalent of carbon source added. The BOD5 equivalent of sodium acetate is 0.52 (mgB0D/mg sodium acetate).

Therefore, when sodium acetate is added as a carbon source, the dosage (mg/L) is 4-CB0D5/CN. CN/0.52.