Wastewater May Not Be a Waste After All

Powering water treatment plants with wastewater itself may seem far fetched, but this technology is on the horizon. Researchers, both globally and at Ohio State, are attempting to use microorganisms in wastewater to power treatment plants.

One of these microorganisms is geobacter sulfurreducens. Discovered in Potomac River sediments in 1987, geobacter are bacteria that can produce an electrical charge by breathing iron and mineral compounds. Geobacter in wastewater breathe in minerals and produce electrons, which are transferred to electrodes on microbial fuel cells (MFC). The fuel cells then power wastewater treatment processes.

The Office of Energy and Environment funded the microbial fuel cells research of Beenish Saba, a graduate student in biological engineering, in 2016. Saba had prior research experience treating textile dye wastewater using constructed wetland and wastewater bioreactors; however, her current research harnesses MFC technology to treat the dye wastewater.

Saba became interested in this field of study in 2013, after reading a paper by Derek Lovley, a microbiologist at the University of Massachusetts known for dramatically increasing the electricity production of geobacter.

“This research piqued my interest in the field of microbial fuel cells, and I started searching for any professor working in this field at Ohio State,” says Saba.

She found her advisor in Ann Christy, a professor of food, agriculture and biological engineering.

Saba says she is grateful for Christy’s guidance in this new and innovative field. MFC scientists analyze how waste converts to energy without additional energy input.

This process provides clean and renewable energy from waste resources, Saba says.

“In biofuels you need biomass or byproduct from agriculture, and in solar or wind energy you need capital investment to make and operate heavy machinery,” Saba says.

However, MFC technology harvests energy from existing sources such as landfills, algal ponds and rice paddy fields.

Her research focuses on the treatment of textile dye wastewater. Dye wastewater from the textile industry can be highly dangerous to the environment if improperly disposed. When discharged into bodies of water, dye wastewater stops the reoxygenation of the receiving water and cuts off sunlight, thereby upsetting aquatic life.

Saba found that two-chambered microbial fuel cells fed with carbon sources could remove – or decolorize -- dyes from the wastewater.

“RB5 (reactive black dye 5) and RBL4 (reactive blue 4 dye) were completely decolorized” Saba says.

The analysis of whether the decolorized wastewater can produce energy awaits further study.

Saba will continue studying in the field of microbial fuel cells, which many researchers are trying to commercialize. Until then, Saba says she would like to pursue a career in teaching so she can educate the next generation of graduates.

Written by Carlee Frank, student communications assistant