In wastewater requiring denitrification, it is often insufficient carbon sources that lead to low removal rates of denitrification, resulting in...TNExceeding the standard, the addition of carbon sources has become a practical approach. Currently, carbon sources typically include methanol, sodium acetate, flour, glucose, and more. This article will compare the most widely used carbon sources, providing an initial understanding of their advantages and disadvantages!
1Methanol
It is widely believed that methanol, as an external carbon source, has low operating costs and low sludge production.No Chinese content provided.Small advantages. There is a phenomenon of nitrite accumulation when methanol carbon source is insufficient. Denitrification rate is faster when methanol is used as the carbon source compared to glucose.3Please provide the Chinese content that needs to be translated into American English.CODPlease provide the Chinese content you would like translated.2.8～3.2。
As current research indicates, Methanol as a carbon source,C/N>5 Achieves good results at times, but it has three drawbacks:
①As a chemical reagent, the cost is relatively high.
②Slower response times, methanol is not utilized by all microorganisms, and it requires an adaptation period after addition until it is fully enriched and achieves its full effect. It is not effective when used as an emergency carbon source addition in wastewater treatment plants.
③Methanol possesses certain toxic effects, and its long-term use as a carbon source can also impact wastewater discharge.
2Sodium acetate
The advantage of sodium acetate lies in its immediate response to denitrification processes, making it suitable for emergency treatment during water plant operations.
Sodium acetate, due to its nature as a small molecule organic acid, Denitrifying bacteria are easy to utilize, with excellent denitrification effects.Please provide the Chinese content to be translated.OK, but due to its high sludge yield and relatively high cost,The sludge disposal issue at the wastewater treatment plant is also a significant challenge, making large-scale addition of sodium acetate into the plant nearly impossible.
3Sweeteners
In carbohydrate substances, wheat flour, sucrose, and glucose are predominant. Since glucose is a simple sugar, it has attracted more research. When carbon sources are abundant, the carbon-to-nitrogen ratio using glucose as the carbon source is much higher than that using methanol as the carbon source. 6:1～7:1The type of carbon source has little effect on the relative reduction rate of nitrate nitrogen, but has a significant impact on the relative accumulation rate of nitrite nitrogen. Glucose was the only carbon source in this study that did not show any accumulation phenomenon.
Gluucose, as a representative of carbohydrate substances, has shown good treatment effects as an external carbon source. However, as a polymeric compound, it is prone to cause an excessive proliferation of bacteria, leading to sludge expansion and increased levels of effluent.CODThe value affects the water quality of the effluent, and compared to aliphatic carbon sources, sugar substances are more prone to the phenomenon of nitrite nitrogen accumulation.
4Sludge hydrolysis supernatant
Biological Conversion VFA Clear liquid obtained from sludge hydrolysis, due to the hydrolysis producedVFA High denitrification rate, with the carbon source readily available from the wastewater treatment plant itself, it not only reduces sludge volume but also addresses the issue of carbon source transportation, making it a currently advantageous carbon source.
Research on the utilization of sludge hydrolysis as an external carbon source has yielded various conclusions, but it is generally believed to be a valuable method as a carbon source for denitrification and nitrogen removal systems. However, for different sludges and varying hydrolysis conditions, the resulting sludge...VFA The composition varies significantly, and due to these differences, the denitrification rate also varies, which is why many studies yield inconsistent results. Therefore, how to process the by-products of sludge hydrolysisVFAStandardizing the application of research is still a significant challenge. Moreover, if hydrolyzed sludge is directly used as an external carbon source, the release of nitrogen and phosphorus during the hydrolysis process must be considered. If this nitrogen and phosphorus is added to wastewater in the form of a carbon source, it will inevitably increase the nitrogen and phosphorus load of the wastewater treatment plant. How to address this issue is another major challenge in utilizing the hydrolysis liquid of sludge.
