What is the main function of a sludge digester?

The primary role of a sludge digester is to reduce the volume of sludge and stabilize it, making this option the most accurate choice. In wastewater treatment processes, sludge accumulates as a byproduct of the treatment of waste. The digester uses processes such as anaerobic or aerobic digestion to break down organic matter within the sludge. This biological decomposition not only leads to a significant reduction in the volume of organic material but also decreases the pathogenic content and makes the residual material less hazardous.

Stabilization is critical because it helps to minimize odors and makes the residual sludge safer for subsequent handling or disposal. A well-functioning sludge digester enhances the efficiency of the entire wastewater treatment system, ensuring that the residual sludge is manageable and compliant with environmental regulations before it is dewatered, further treated, or disposed of.

The other functions listed—producing clean water, filtering out large solids, and measuring chemical levels—are not primary functions of a sludge digester. Clean water production typically occurs in secondary treatment processes, while filtration is usually performed by screens or other pre-treatment equipment. Chemical level measurements are relevant to various stages of treatment but do not pertain specifically to the digesting process.