What percentage should TSS typically represent VSS in wastewater treatment?

In wastewater treatment, Total Suspended Solids (TSS) and Volatile Suspended Solids (VSS) are critical parameters used to evaluate the quality of the suspended solids in the water. TSS represents the total amount of solid material in a sample, while VSS refers specifically to the portion of the solids that can be volatilized or burned off, which typically includes organic matter.

A typical value for VSS as a percentage of TSS is around 75%. This means that out of the total suspended solids present in the wastewater, approximately 75% can be classified as volatile, indicating the organic content of the wastewater. This high percentage is significant because it shows that a large portion of the solids is likely to be biodegradable, which is a key factor in the treatment process, especially in biological treatment methods where microorganisms break down organic materials.

The reasoning behind this typical ratio is also tied to the composition of typical wastewater, where organic materials (such as food waste, human waste, and other biodegradable substances) are predominant. In various types of wastewater, especially municipal, the organic matter contributes significantly to the total solids content, justifying the 75% figure.

The other percentages provided do not accurately reflect common conditions observed in wastewater treatment processes