Which method is commonly used to filter out true color from water samples?

The method commonly used to filter out true color from water samples is chemical coagulation. This process involves adding coagulants to the water, which encourages the particles and dissolved substances causing the color to clump together, forming larger aggregates. These aggregates can then be removed through sedimentation or filtration. Chemical coagulation is particularly effective for addressing the small and dissolved particles that contribute to true color, which may not settle effectively through physical methods alone.

While centrifugation, activated carbon treatment, and physical sedimentation are also techniques used in water treatment, they serve different purposes or address different types of contaminants. Centrifugation is effective at separating particles from liquids based on density but may not effectively remove dissolved color. Activated carbon treatment can adsorb a wide range of organic contaminants, including some color-causing compounds, yet it may not be as efficient specifically for true color as chemical coagulation. Physical sedimentation focuses on gravitational settling of larger particles and is less effective for dissolved substances causing true color. Thus, chemical coagulation is the most suited method for reducing true color in water samples.