What is a common cause of clogging during preliminary treatment screening?

A common cause of clogging during preliminary treatment screening is indeed the presence of large debris. During this initial stage of treatment, screens or grates are designed to remove sizable objects and materials that could disrupt subsequent processes. When large debris—such as sticks, leaves, plastics, or rags—enters the screening area, it can get trapped. This not only clogs the screens but can also lead to increased maintenance needs, potential damage to equipment, and a decrease in system efficiency.

In contrast, while excessive water flow can contribute to operational challenges, it typically does not directly cause clogging. High temperature is more relevant to biochemical processes than to the physical mechanisms of clogging at the preliminary stage, and low chlorine levels pertain to disinfection processes rather than initial screening issues. Hence, the most significant threat to smooth operation during preliminary treatment is indeed the presence of large debris.