US researcher develops energy efficient waste-water treatment technology

Researcher at Missouri University of Science and Technology in the US have developed an energy-saving technology to treat wastewater into freshwater, which is claimed to be more efficient than the conventional methods.

Invented by Missouri S&T professor of civil, architectural and environmental engineering Dr Jianmin Wang, the technology claimed to be used at existing wastewater treatment plants as well.

Nearly 8% of energy consumption in the US is used for wastewater treatment, most of which is used to aerate the tanks where the treatment process is conducted.

Traditional treatment facilities maintain an oxygen concentration of 2mg/l to feed the microorganisms that consume the waste, which can be reduced to 0.5mg/l to save energy, according to the researcher.

Contrary to conventional belief, this is likely to ensure long life for the micro-organisms and ensure the same results at 30% less energy spent over oxygen infusion.

Another treatment process called Alternating Anaerobic-Anoxic-Oxic (A3O) process has also been developed by Dr Jianmin Wang which does not involve the use of chemicals. Yet it "can achieve superior effluent quality since it can remove organic pollutants plus nitrogen and phosphorus nutrients."

Wang’s third invention is a self-mixing anaerobic digester, which enable transformation of wastewater sludge and other organic waste to biogas energy.

A combination of his technologies is expected to produce an additional 10% of energy instead of 27% net power consumption of wastewater treatment industry currently, Wang claims.

The treated water from Wang-invented technologies are, however, only suitable for irrigation at present. It can be modified to produce potable water as well.

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Image: Missouri S&T professor develops new wastewater treatment technologies that save energy. Photo: Courtesy of Missouri University of Science and Technology.