If GAC loss exceeds what measurement, backwashing procedures should be evaluated?

Granular Activated Carbon (GAC) is used in water treatment processes primarily for the removal of organic compounds, chlorine, and other impurities. When GAC is employed in filtration systems, it is crucial to monitor the loss of the media, which can occur due to backwashing and other operational factors.

When GAC loss exceeds 2 inches or 50 mm, it signifies that a significant amount of the filtering media has been displaced or lost due to the physical cleaning process of backwashing. Evaluating backwashing procedures at this level is essential to ensure that the media remains effective and that the filtration system is operating efficiently. Excessive GAC loss can lead to reduced treatment effectiveness, an increase in the need for media replacement, and potential contamination of water, therefore warranting a reassessment of backwashing techniques to optimize performance and media preservation.

Other measurements either indicate lesser loss or are beyond typical operational concerns for GAC, making them less relevant to the evaluation of backwashing procedures. Monitoring for loss at the 2 inches/50mm mark provides a critical threshold that allows for corrective measures to be implemented before greater losses occur.