What condition can prevent effective disinfection due to particles suspended in the water?

Turbidity is a measure of the cloudiness or haziness of water caused by suspended particles such as silt, clay, and organic matter. High turbidity can hinder the effectiveness of disinfection processes, such as chlorination or ultraviolet (UV) treatment, because the particles can shield microorganisms from the disinfectant's action. When water has high turbidity, any microorganisms present may not be adequately exposed to the disinfectant, thereby reducing the overall efficacy of the treatment. Additionally, the presence of suspended solids can absorb and react with disinfectants, further diminishing their effectiveness.

In contrast, clarity refers to the purity of water, which is typically associated with lower turbidity but does not specifically address the presence of suspended particles. Contamination generally relates to the presence of harmful substances or microorganisms in water, which can be a separate issue from turbidity. Hardness refers to the concentration of calcium and magnesium ions in water, which does not affect disinfection efficacy in the same way that turbidity does. Thus, turbidity is the specific condition that can significantly impede effective disinfection in water treatment processes.