What happens during the backwash process in water treatment?

During the backwash process in water treatment, the flow of water is reversed through the filtration media. This reversal of flow is essential for cleaning out sediment and trapped particles that have accumulated in the filter during regular filtering operations. Over time, these particles can clog the media, reducing its effectiveness and the quality of water being treated.

By reversing the flow, the trapped particles are dislodged and flushed out of the filter, allowing for the restoration of the filter's efficiency. This process not only helps maintain optimal performance of the filtration system but also prolongs the lifespan of the media used in water treatment, ensuring consistently high-quality water output.

In contrast, the other provided choices pertain to different actions unrelated to the backwash process. Heating water for purification focuses on thermal treatment rather than the mechanical cleaning of filter media. The addition of new chemicals targets disinfection or treatment but does not involve the physical cleaning aspect of filtration. Discharging water from the system typically refers to the release of treated or waste water, which is also not part of the backwash function.