Why does sludge age?

2020/11/09

Introduction

Everyone who does operation and maintenance has thought about the aging sludge. Watching a pond of mud slowly deflocculate, change color, and foam, it will feel very dangerous.

What is sludge aging?

Under aerobic conditions, microorganisms can decompose part of the organic matter in the water to provide energy, while at the same time synthesize another part of the organic matter into cellular material to strengthen itself. These two situations are carried out simultaneously.

When the organic matter in the water is insufficient, you have to decompose the part of the cell material you just synthesized to produce energy. This is called endogenous respiration, which will produce endogenous respiration residues. When endogenous respiration dominates, it is the aging of the sludge. Start.

Causes of aging sludge

Mainly due to malnutrition of sludge. When the sludge load becomes high, the catabolism and anabolism are fast when the organic matter is sufficient. If the sludge load is reduced at this time and the organic matter in the wastewater is insufficient, it will be like braking after strenuous exercise.

Moreover, the concentration of sludge was increased when the load was high before, but now there is too much porridge, the sludge becomes malnourished, the decomposition effect is lack of raw materials and becomes weak, anabolism is dominant, and dissolved oxygen is also used as endogenous respiration .

How to prevent sludge aging?

Try to avoid low-load operation of the biological treatment system, which can increase the concentration of aerobic reaction substrates in the influent or reduce the concentration of activated sludge.

Reducing the age of sludge can also effectively prevent aging, reduce the residence time of sludge in the secondary settling tank, and avoid gaps and excessive flow fluctuations in the sludge discharge method, but also take into account the nitrifying bacteria.