Question 283Motor Plants - Assistant Engineer

The correct answer is D) Water. During the sludge discharge cycle, water is typically used as the primary operating medium. This is because water is an abundant, readily available, and inexpensive fluid that can effectively facilitate the movement and discharge of sludge from the system. The other options are not correct because: A) Light phase liquid and B) Heavy phase liquid are not commonly used as the primary operating medium for sludge discharge, and C) Hydraulic fluid is typically reserved for more specialized hydraulic systems, not for general sludge discharge operations.