The purpose of the Reverse Osmosis Activated Carbon System (ROAC) is to ensure that any free chlorine and organics that may have passed through the primary treatment system have been removed.
The ROAC systems consist of several fiberglass reinforced plastic (FRP) or welded carbon steel pressure vessels that are filled with the appropriate amount and type of activated carbon to ensure proper removal of the materials of concern.
The water from the Reverse Osmosis Pretreatment System, where it has been adjusted for proper pH and ORP, is pumped to the carbon filter units for removal of any residual organics of free chlorine.
A control system, based on a Siemens PLC, controls all the functions of the ROAC system, including backwash and return to operation.