What characteristic do colloidal particles have when discussing turbidity?

Colloidal particles play a significant role in the discussion of turbidity in water treatment because they possess an electrical charge that helps maintain their suspension in water. This electrical charge creates repulsive forces between particles, preventing them from aggregating and settling to the bottom.

This behavior is crucial in understanding turbidity, as it directly affects water clarity and quality. Turbidity measures the cloudiness or haziness of a liquid caused by large numbers of individual particles. Since colloids remain suspended due to their charge, they contribute to elevated levels of turbidity, making it essential for water treatment processes to remove or manage these particles effectively.

The other options do not accurately describe the characteristics of colloidal particles in relation to turbidity. Not all colloidal particles are negatively charged, and many can have neutral or positive charges. Additionally, colloidal particles do not settle quickly; rather, they remain suspended for extended periods due to the electrostatic forces in the water. Lastly, while colloidal particles are small, they are typically smaller than many pathogens, which further highlights their unique characteristics in suspension.