In 2008, ADSSC, the sewage and sanitary authority in Abu Dhabi, decided to convert two of the existing concrete emergency storage tanks at Mafraq Wastewater Treatment Plant into SBR to treat 50,000 m³ per day of primarily treated sewage, thus increasing the secondary treatment capacity of the plant.

Napier-Reid worked closely with Concorde-Corodex, the general contractor, to design and supply a two train SBR system that would treat the wastewater to the effluent specification.

Each SBR train includes one influent magnetic flowmeter & motorized plug valve, one fine bubble aeration system complete with membrane fine-bubble diffusers, four submersible mixers, two submersible waste sludge pumps, one magnetic flowmeter for monitoring waste activated sludge, and two dissolved oxygen analyzers.

We also supplied two duplex stainless steel SBR decanters per train, each 18m long for a total weir length of 36m. The decanter travel speed is controlled by VFD to maintain constant decant rate from the top water level to the bottom water level.

Construction is on schedule and commissioning is expected in August 2009.