students in lab

The idiom "there must be something in the water" can be applied a lot of ways. One senior design team wants to see if they can do something about the 'something'. They are researching the potential for one new technology designed to reduce nitrate levels in wastewater.

The team is working with Ofir Menashe, CEO of Bio-Castle, an environmental biotech company in Israel. The company's Small Bioreactor Platform (SBP) capsule technology is helping them to do it. Menashe provided the NatiCap De-nitro capsules, which contain denitrifying bacteria that convert nitrate into nitrogen gas, thereby reducing the nitrate levels in wastewater effluent, and in effect reducing the nitrate levels in our waterways.

Excess nitrate levels cause issues such as eutrophication in certain aquatic systems, such as in Maryland, where "dead zones" occur when elevated nitrate levels lead to targeted extinction events.  

First: what is eutrophication?

"It starts with excess nutrients in runoff from places like farms and wastewater treatment plants; algae feed on these nutrients, so when the nutrients are in excess the algae begin to grow out of control, creating toxic algal blooms," added Ashley Richman, a civil and environmental engineering major and team member. "When the algae die, they decompose and use up oxygen, making it difficult for other things like fish to survive in that habitat. This creates these dead zones."

Where do the capsules come in? They are a relatively new technology implemented in wastewater treatment, specifically de-nitrification, or the reduction of nitrate.

"BioCastle creates several types of capsules used for the removal of individual contaminants from wastewater. For instance, there's one capsule specifically for the removal of petroleum, added teammate Lyle WinklerPrins. "The BioCastle technology we are using is specifically for de-nitrification, so that's what we are researching."

Nitrate levels are traditionally high in wastewater discharge, so Wissahickon Creek water, which contains a high concentration of wastewater effluent from surrounding treatment plants, was a prime candidate for further study. They also performed testing on wastewater effluent from a nearby wastewater treatment plant. The team built a bench-scale model bioreactor to test the water samples with capsules from BioCastle in the fifth-floor laboratory (right).

"In addition to this becoming a full-blown research project, we've had to change course a few times," WinklerPrins said. "It's taught us to manage our time, for sure."

Richman, WinklerPrins and teammates Maria Luciani and Julia Scott, initially discussed their senior design idea with faculty advisor Rouzbeh Tehrani, and eventually connected with Ofir Menashe, the BioCastle CEO.

"This is such a great opportunity for these students to touch on entrepreneurship and to gain some experience in new technology implementation, study design, establishment and operational activities," added Menashe. Menashe communicates regularly with the team via email and Skype sessions to both brainstorm and plan the shipping of SBP capsules to Philadelphia.

While many teams aim to have students arrive at some sort of engineering solution, another avenue is to simply pass the baton: engage an incoming team to take your technology and iterate.

"We absolutely want to hand this off to a new team. We're hoping to have more full, thorough research on how this technology performs in a continuous reactor," WinklerPrins said.

"Particularly, we're looking at hydraulic retention time: how long does it take this technology to take water with a certain concentration level to another nitrate concentration level? And the next team can use that hydraulic retention time to test the efficiency of the capsules at several initial nitrate concentrations using a continuous flow."