What is the best solution if the volatile-acid-to-alkalinity ratio increased to 0.3 in a digester?

The best solution when the volatile-acid-to-alkalinity ratio in a digester increases to 0.3 is to thicken the raw sludge. This ratio indicates that there is an accumulation of volatile acids relative to the alkalinity, which can lead to a condition known as acidification in the digester. By thickening the raw sludge, you are essentially decreasing the hydraulic retention time and increasing the concentration of solids and microorganisms in the digester. This process helps to balance the volatile acids produced by the degradation of organic material, providing better conditions for methane production and preventing further upset in the digestion process.

Enhancing the thickness of the sludge encourages more effective digestion, as the microorganisms will have a richer environment to process the organic matter, thus helping to stabilize the volatile-acid-to-alkalinity ratio. Maintaining a balanced ratio is essential for optimal biogas production and digester efficiency.