What is the process of reversing the flow of water back through the filter media called?

The process of reversing the flow of water back through the filter media is known as backwashing. This procedure is essential in maintaining the efficiency and longevity of water filtration systems. During normal operation, water flows through the filter media, where suspended particles and contaminants are captured. Over time, these particles accumulate, leading to decreased flow rates and efficiency of the filter.

Backwashing involves reversing this flow, allowing the trapped contaminants to be removed from the filter media. This is typically accomplished by temporarily redirecting the water flow, often using clean water, to flush out the accumulated materials. As a result, the filter media is cleaned and can continue to effectively purify the water.

This process differs significantly from other options. Filtration is the standard process of separating solids from liquids, which precedes backwashing. Flocculation and coagulation refer to processes that involve the aggregation of particles in water to form larger clumps that can be more easily removed, often before filtration takes place. Thus, backwashing specifically addresses the maintenance of the filter media itself, highlighting its crucial role in water treatment operations.