What is a Slow Sand Filter used for?

A Slow Sand Filter is primarily used for the treatment of drinking water, particularly effective in removing particulate matter and microorganisms from low turbidity waters. The design of these filters allows for the development of a biological layer, or schmutzdecke, on the surface of the sand, which plays a crucial role in the filtration process. This layer consists of microorganisms that help to break down organic material and trap pathogens, including giardia.

When dealing with low turbidity waters, the slow filtration process allows for effective removal of contaminants, ensuring that the water is safe for consumption. This method is particularly advantageous because it operates at a slower rate compared to rapid sand filters, which are more suited for higher turbidity levels and require frequent backwashing and maintenance.

The correct answer highlights the Slow Sand Filter's suitability for treating low turbidity waters, providing a reliable means of removing specific pathogens while maintaining water quality. Other options are more aligned with other filtration methods, such as rapid filtration techniques not suited for slow sand filtering applications.