College of Engineering News Room

Environmental Engineering Award for On-Site Wastewater Project

Students and faculty work on a CEE wastewater treatment site

By Brad Stager

Solving the problem of environmental pollution from domestic wastewater sources like septic tanks is the focus of a University of South Florida civil and environmental engineering research project that has won a prestigious award from the American Academy of Environmental Engineers and Scientists (AAEES).

The project’s approach to treating wastewater is described in its name: Hybrid Adsorption Biological Treatment System (HABiTS) for Nitrogen Removal in Onsite Wastewater Treatment. It employs passive biofilters that absorb nutrients in household wastewater from sinks, showers, laundries and toilets, using low-cost materials like natural zeolite minerals, scrap tire chips, elemental sulfur pellets and crushed oyster shells.

AAEES recognized the onsite wastewater system with the Grand Prize in the University Research category of its Excellence in Environmental Engineering & Science (E3S) awards, which will be presented at the National Press Club in Washington D.C.

Removing nutrients such as nitrogen from wastewater is an area that Professor Sarina Ergas has focused on in her research and teaching at USF. Ergas said that recognition by AAEES is validation that the hard work of the team of students and faculty involved in the project contributes to advancing wastewater mitigation.

“We’re very, very excited about this award because of its relevance to global environmental problems that are also major issues in Florida,” she said.

Ergas adds that progress in nutrient removal is needed because about one third of the wastewater in Florida is treated in septic systems, which contribute to harmful algal blooms, loss of seagrass, fish kills, nitrate contamination of well water, and other problems affecting Florida’s health, environment and economy. 

James Mihelcic, professor and Samuel L. and Julia M. Flom Endowed Chair in Civil and Environmental Engineering at the University of South Florida is also involved in the HABiTS project. Water quality and sanitation are research areas of interest for him and are reflected in the project that evolved from a laboratory bench model to a larger-scale pilot system located at a Hillsborough County Water Resources Department wastewater treatment facility.

CEE students and faculty work on a project at a test wastewater facility

The system demonstrated its ability to treat wastewater from homes and businesses. He said recognition from AAEES raises the profile of USF’s wastewater research, but there is still much to be done when it comes to making new wastewater treatment technology available in the marketplace.

“We need more of these demonstrations and also a commitment by state and local government officials and homeowners to deal with the problems of nutrient pollution,” Mihelcic said. “Some of these are associated with the effluent of millions of improperly installed and maintained septic tank systems that are found in Florida that continue to contaminate our springs, streams and groundwater.”

The HABiTS pilot project is part of a $2.5 million EPA funded Center for Reinventing Aging Infrastructure for Nutrient Management. A 500-gallon septic tank was installed at the Northwest Regional Water Reclamation Facility in Hillsborough County.

Effluent — wastewater released from a treatment facility — was siphoned off from the facility pipeline to the septic tank for student researchers like Ph.D. candidate Michelle Henderson to work with. She says one of the advantages of the HABiTS system is its simplicity, which will hopefully lead to greater adoption as an onsite wastewater treatment system.

“We should be excited about this,” Henderson said during a tour of the project in 2018. “We’re treating this wastewater and it’s simple; there’s minimal inputs for the homeowner after they install the system.”

Researching and solving water-related issues is the mission of the USF Water Institute, where Ergas and Mihelcic also have affiliated faculty standing. Similarly, Director of the Office of Sustainability at the Patel College of Global Sustainability Kebreab Ghebremichael — who also teaches at the College of Engineering — is involved in the HABiTS project.

“If this technology is well-developed and we show it works, it can help address significant issues of our time,” Ghebremichael said.

Other than the USF team, the HABiTS pilot project was developed in cooperation with Hillsborough County Water Resources Department and engineering consulting firm Hazen and Sawyer.