What is the purpose of screening in sewage treatment?

Screening is used to remove large solid objects from sewage, such as sticks, leaves, and plastic. This helps to prevent damage to the equipment used in the treatment process and ensures that smaller particles can be treated effectively.

A strong answer should directly address the approved learning objective to describe screening and grit removal as early stages of sewage treatment. This question belongs to Waste water treatment within Using the Earth's resources and obtaining potable water, so the response should use that exact curriculum context rather than a generic statement. The answer is correct when it names the key idea, explains the link to sewage, and keeps the wording specific to AQA GCSE revision.