(379p) Inquiry-Based Learning for Students in the Senior Unit Operations Course with a Hydroponic Plant Growth Experiment

In 2011, the concept of a Water-Energy-Food nexus was first used and identifies that water, energy and food are interconnected. As the human population grows there will be an increasing demand of food and energy needed which puts a major strain on water resources as there is a finite amount of freshwater that can be used. The National Academies has highlighted that this is a new direction that chemical engineering should pursue.¹ One of the methods to increase food supplies to begin addressing the Water-Energy-Food nexus challenge is developing hydroponic- and aquatic-based technologies.¹

As part of senior unit operations, one group of students developed their own experiments to investigate operating conditions for a hydroponic system. In the second semester of the two-semester senior unit operations course, seniors were tasked with choosing a topic, developing their own experimental plan, identifying variables to change and quantifying the effects of different conditions. Several variables tested for the hydroponic system were seed density, water flow rate and nutrient concentration and the growth of microgreens was monitored. Experiments were completed over several 2-week growth cycles and every cycle had 12 conditions tested in triplicate. The mass of drained growth pads was measured every other day and plant height and dry mass were measured at the conclusion of each growth cycle. Experiments demonstrated variations in plant growth based on the different growing conditions. Concurrently, students appreciated the ability to create their own experiment and investigate a topic of interest to them. The hydroponic growth experiment presents a new lab experiment that can be integrated into the chemical engineering curriculum and a means to expose chemical engineers to a new topic relevant to the field.

¹ National Academies of Sciences, Engineering, and Medicine. 2022. New Directions for Chemical Engineering. Washington, DC: The National Academies Press. https://doi.org/10.17226/26342.