In typical primaries sludge, how much of the total solids are usually volatile?

In typical primary sludge, the percentage of total solids that are volatile typically falls between 70% and 80%. Volatile solids refer to the organic portion of the sludge that can decompose under heat, which includes biodegradable materials like fats, oils, and organic compounds. The high range for volatile solids indicates that a significant amount of the sludge is made up of substances that are breakable through biological processes. Understanding this composition is critical in wastewater treatment, as it informs processes like digestion and stabilization, where organic matter is minimized, and pathogens are reduced. The presence of such a high percentage of volatile solids suggests that primary sludge is relatively rich in organic material, which has implications for how it will be treated and processed.