Date of Award
Santa Clara : Santa Clara University, 2017.
The St. Francis Retreat Center, which serves over 7000 people each year, has had issues with the health of Flint Lake, located on their property, during the drought season. By utilizing a nearby water well, the retreat center looks to recharge the lake and sustain its water levels, essentially restoring its natural ecosystem. The issue is that the well water is contaminated with high amounts of nitrates, which is not only an issue for the lake’s health, but also is very unsafe for human consumption. In order to design a water treatment system that is ecofriendly, sustainable, and cost-efficient, the team looked to construct and test the effectiveness of a denitrifying woodchip bioreactor. This design will serve as a prototype for a much larger implementable system that will be able to handle the flow rates from the water being pumped from the contaminated well. To run the tests, a 300 gallon steel tank served as the bioreactor apparatus that facilitated the process of denitrification using heterotrophic bacteria which consumes the nitrates in the water and synthesizes them into nitrogen gas. The prototype demonstrated that denitrifying bacteria, using the woodchips as a growth source, effectively reduce nitrate levels to meet government-mandated standards, and can be implemented on a larger scale.
Highlander, Andrew and Johnson, Patrick, "Woodchip denitrification bioreactor for reducing nitrate in contaminated well water for St. Francis Retreat Center" (2017). Civil, Environmental and Sustainable Engineering Senior Theses. 61.