Nicodemus Wilderness Project -- Global Registry of Apprentice Ecologists

Carbon capture sequestration, bioremediation, hydrogen fuel cells, reclamation techniques--- these are just a few of the things that excite me the most. As a first year civil engineering major at the University of Texas at Austin, I bridge my passion for engineering and my drive to solve environmental issues together in the field of environmental engineering to complete my number one goal--- creating lasting change for a more sustainable world.

My project was conducted in the field of phytoremediation in one of the greenhouses on the UT campus. Phytoremediation, a form of a bioremediation, is the use of living plants to remove or convert harmful compounds into benign substances. Today, there are countless opportunities for contaminants to enter soil. Whether from industrial operations, run off water, or strip, surface, and open-pit mining practices, toxic metals often find their way into soil as an unfortunate byproduct of human economic development. Phytoremediation offers a unique solution to the pressing problem created by the presence of toxic metals in soil. Plants known to be effective phytoremediators can be planted in sites with high concentrations of toxic metals and remove them from the soil with minimal human effort, and even offer the possibility of retrieving the metals accumulated by hyperaccumulators afterward through smelting. However, to be an effective phytoremediator, a plant must not only be able to immobilize the contaminant, but to do so without negative impacts on its growth. If a plant can't withstand the dose of the toxin, there is no way its growth rate will be sufficient to remove an adequate amount of said toxin from the soil.

Due to its detrimental effects on human health and the possibility of bioaccumulation, I chose to focus on lead as a contaminant and sunflowers as phytoremediators. Prior studies have indicated that sunflowers are hyperaccumuators, meaning that they can accumulate various compounds in their tissues after absorbing them through their root system, and these are hardy plants that are both aesthetically pleasing and minimize the risk of accidental ingestion of plant parts by humans, unlike many other phytoremediators which can also be grown as crops. Through my project, I wished to test the effectiveness of sunflowers as phytoremediators of lead contaminated soil, and did so by assessing the impact on growth in an environment containing varying concentrations of lead.

In order to determine the effect of lead on the growth of sunflowers (Helianthus annuus), I cultivated the sunflowers over the course of four weeks in soil with lead concentrations of 600 ppm Pb(NO3)2 (lead nitrate) and 100 ppm Pb(NO3)2. Solutions of these concentrations were chosen because the EPA deems up to 400 ppm safe for soil in children's play areas, so in order to truly understand the phytoremediative abilities of the sunflower, it needs to be studied at both relatively low and relatively high concentrations. I also used a control treatment where no Pb(NO3)2 was added. After the sunflowers' first four weeks of growth, the period in which their rates of accumulation are at their peak, I took measurements of each of the shoot lengths and the length of the largest lead of each sunflower, and used the one-way ANOVA statistical analysis test to examine my results.

Surprisingly, sunflowers grown in soil containing lead nitrate had faster growth rates than those grown in average potting media, suggesting that in the presence of nitrate, sunflower cultivation could prove to be extremely effective when it comes to immobilizing soil contaminants like lead.

While my project does have huge ecological implications in the field of reclamation, it had just as large (maybe even larger) impacts on me. As a person, I am passionate about environmental protection, but as a scientist and engineering, I am determined to DO something to make my dream of a sustainable world a reality. The research I conducted proved more difficult than I imagined with more changes in experimental design than I can count and more problem solving than I have ever had to encounter for a project. Despite the trials and tribulations, my dedication for finding innovative solutions has only grown stronger. Contaminant fate and transport is an extremely important aspect of environmental stewardship, and the remediation of contaminated land is essential for ecological health and welfare. I believe that the research I conducted through this project indicates the possibility of a solution that will effective minimize the damage caused when anthropogenic activity causes compounds activity caused compounds containing heavy metals to leach into soil. This was quite possibly the best learning experience I have ever had because it taught me that failing many, many times is all part of the scientific process, and that with every failure comes more insight into how to solve the problem at hand. My desire to research in the field of environmental science and ecology have only been affirmed through this project and I am ecstatic to see which problem I will tackle in my next one.

This project has inspired me, and I fully intend to continue researching solutions to environmental and ecological issues throughout the next four years of college and plan on completing environmental engineering research through graduate school as well as in my doctoral education. It will be difficult, but equipped with my passion for engineering and the environmental and my drive to change the world, I am more than ready for the challenge.