Alcoa Wastewater System ‘Saves More Than $7m Annually’

Alcoa and the Saudi Arabian Mining Company (Ma’aden) have completed an engineered wetlands wastewater management system in Saudi Arabia that the companies say will reduce water demand by about 2 million gallons per day and save more than $7 million annually that would otherwise be used to purchase fresh water.

The system at the Ma’aden-Alcoa joint venture project site is the first of its kind, the companies say.

An Alcoa spokesperson tells Environmental Leader that the company is considering employing the technology at other Alcoa locations globally, including in the US.

The Alcoa-designed and engineered technology — called a natural engineered wastewater treatment system — collects sanitary and industrial wastewater and then cleans and disinfects it without using chemicals or creating water discharge and odors associated with conventional tank systems.

The system includes three steps (pictured). First, an anaerobic treatment tank breaks down and separates organic material in the water. Second, a passive engineered wetland utilizes vegetation for further treatment of organics and removal of nitrogen and metals. Third, a cell housing bauxite-based technology disinfects and polishes the water.

Alcoa says the result is water treated to the same or better quality as that of a conventional system. The water will then be reused in the manufacturing process and for irrigation at the Ma’aden-Alcoa aluminum complex at Ras Al Khair. The complex includes a refinery, smelter and rolling mill.

This sustainable technology, demonstrated via full-scale deployment at the Alcoa Technical Center near Pittsburgh, Penn., is now being considered for other wastewater treatment applications throughout Saudi Arabia, Alcoa says.

Alcoa technical experts developed the system to mimic the physical, chemical and biological processes of natural wetlands. In addition to saving water and money, the innovative design was constructed six months faster than a conventional tank-based system and eliminated an estimated 1,000 metric tons of steel for piping and tanks, Alcoa says.

The project is expected to be fully operational by the end of July this year.

Earlier this month, GE said it successfully pilot tested its low-fouling reverse osmosis membrane in Asia. The company says the new membrane purifies tough-to-treat water such as wastewater from industrial processes can reduce time between cleanings by up to 50 percent.