Description

Floating treatment wetlands (FTWs) are a promising approach to mitigate the harmful effects of eutrophication from urban stormwater nutrient pollution. FTWs are nature-based treatment systems consisting of aquatic plants anchored into a floating mat. Plant roots hang down into the water beneath the mat where contact with the water facilitates nutrient uptake. As nature-based treatment systems, FTWs experience inherent operational uncertainties due to the environment in which they operate. This research seeks to fill knowledge gaps to strengthen emerging data sets and help ensure success of future projects through use of evidence-based design. We conducted small-scale studies over three years, establishing outdoor FTW mesocosms on Missouri University of Science & Technology campus grounds. The main goal was to assess nutrient removal from artificial stormwater within mesocosms, comparing the effectiveness of FTW mesocosms to controls, under conditions similar to those observed in natural ponds. Objectives were to (1) evaluate nutrient fate and perform a phosphorus mass balance within mesocosms (2) evaluate three native plant species for suitability in FTWs, and (3) compare three plant harvesting and management strategies for nutrient removal efficiency. Water, plant biomass, and periphyton were analysed to determine nutrient fate within the mesocosms. Both macrophytes and microorganisms appear to be major mechanisms of nutrient removal from the water, indicating that FTWs show promise in helping to alleviate the negative impacts of eutrophication from nutrient rich urban stormwater. A follow-up field study is currently being conducted in a highly impacted local pond in Rolla, MO. The pond study thus far demonstrates good plant survival over winter and robust biomass gain across many plant species.

Floating treatment wetland mesocosm study on Missouri University of Science & Technology campus grounds.

Speaker: Carla A Campbell

Carla Campbell is a PhD Candidate in the Department of Civil, Architectural and Environmental Engineering at the Missouri University of Science and Technology. She is a registered professional engineer in the state of Missouri and a member of both the Water Environment Federation and the American Geophysical Union. She received her Bachelor of Science in Civil Engineering from the University of Missouri at Rolla and worked as a consultant in transportation and water resources engineering for several years before returning to Rolla to obtain her Master of Science in Environmental Engineering. After completing her master’s degree, Carla accepted a faculty position as a Lecturer at the University of Missouri-Rolla where she coordinated and taught courses in engineering mechanics, engineering design, and environmental engineering. After taking a break from her career with the birth of her youngest child, she returned to graduate school to complete her PhD in Environmental Engineering with a focus on urban stormwater quality.