How Our Work is Responsible and Beneficial for the World
Several features of the design and implementation of the NNBS came directly from suggestions that stakeholders, experts, and activists made during meetings with UMaryland iGEM. Amongst the highest priorities of all groups, the NNBS must be cost effective for small and large farmers. This was integrated into the design in several ways. The monitoring system features an inexpensive sensor, reducing the cost of materials. The system is seated underground so that it covers no real land area, meaning that the NNBS does not take away room for crops from the farmer. The scalability of the reactor vessel also ensures that each NNBS is implemented according to the needs of each user, meaning that this technology will also be affordable to small farms that do not pollute on a large scale.
Meeting with Dr. Jose-Luis Izursa inspired the team to use a biofiltration system with silica encapsulated alginate beads. Dr. Izursa is an expert in biofilters and is an environmental science and technology lecturer. It was Dr. Izursa’s suggestion that this technology exists and that its function compliments the needs of our system. Utilizing a biofilter allows the bioreactor to remediate a continuous flow of water, making it possible for the system to be implemented along bodies of water. In this way, the opinion of Dr. Izursa had a direct influence on the final design of the NNBS.
Agricultural drainage canal
Due to the high solubility of nitrates, it is important to take into account the effect of soil leaching and percolation. When it rains, as it does often in the state of Maryland, the nitrogenous components of fertilizer on the plants and in the soil dissolve. The dissolved nutrients transit into major waterways in two distinct ways.
Plant roots uptake leached nutrients that dissolve into the soil through rain, but there is also leeching that extends past the surface of the soil. As rain falls, water percolates through the soil, and with it goes the dissolved nitrates. These nitrates slowly, but steadily flow underground into the water table. Here, there is continuous subterranean flow. Over the course of years, this polluted water will feed into streams, rivers, and finally an estuary. Large quantities of nutrients are also left behind, embedded within the soil particulate of a water table. In this way, nutrient pollution can remain within a land mass, long after fertilizer has been distributed over it.
The other way nutrients runoff into water bodies is through agricultural runoff. Most modern farms have technologically advanced irrigation systems, meaning that the soil is ubiquitously well hydrated. When rain falls on an area with hydrated soil, water is most likely to runoff directly into streams that feed into larger bodies of water. Farms typically also have drainage canals that facilitate transit to a local river or stream. As the water flows, nutrients from the surface of the plants and soil dissolve into the rain and are carried away. It is important to note that nutrients that runoff reach waterways, such as the Chesapeake Bay, much faster than the nutrients that leach into groundwater. Runoff avoids the slow, stifled flow of underground currents. Instead, agricultural runoff is diverted from farms, directly into moving water. This means that the rate of change of nutrient pollution in a body of water is largely determined by the quantity that is transported via runoff.
Because of this nitrate transport phenomena, UMaryland iGEM designed a bioreactor system that remediates bodies of water where agricultural runoff feeds into. By using a moving, surface level water source, it is more feasible to accurately measure the presence of dissolved nutrients. With proper analytical tools, it is also much simpler to account for the impact that the NNBS is having on nutrient collection downstream. For nutrients leached into soil below root systems and in the water table, a different approach should be taken. The long term nature and depth of groundwater flow insights a solution that involves well-drilling and excavation. This approach is not within the scope of UMaryland iGEM 2022’s project, and further research should be done into remediating polluted soils.
Integrated Human Practices
Nutrient pollution is a huge problem in the state of Maryland, and there are many federal, state, and private organizations dedicated to mitigating this. To better understand the scope and implications of this problem, UMaryland iGEM interviewed several experts in the field. Their insights were incredibly helpful and their recommendations were directly incorporated into the Nitrate Neutralizer Bioremediation System.
Primary Areas of Stakeholder Engagement & Input
- Current State of MD Agriculture Sustainibility
- Current Strategies Used
- Improvements to be Made
Dwight Dotterer, Maryland Department of Agriculture, 8/9/22
How Our Team Reflected & Integrated:
The first expert UMaryland iGEM met with is Dwight Dotter, Nutrient Management Program Administrator at the Maryland Department of Agriculture. The focus of this meeting was to learn more about the scope of nutrient pollution as a problem and what might be the best way to tackle the problem. He explained to us that the recent legislature in 2013 and 2015 was made to focus on phosphorus as a pollutant in the Chesapeake Bay and there has been significant ground made in bioremediation. However, there have not been similar ventures directed toward reducing nitrate pollution. The systems that farmers prefer for nitrate bioremediation are passive systems that pull nutrients from water/runoff, and are subsidized by the government. Mr. Dotterer also explained that there are not enough ways to reclaim and recycle nutrients once they are used, and the Maryland State government is highly interested in technologies that enable this. To adhere to these end user preferences, we designed a Bioremediation system that passively recovers nitrates from agricultural runoff. If this technology succeeds and is developed, it would ideally go through a review process where it would be used as apart of WIPs and paid for through government subsidy.
Jose-Luis Izursa, UMD Senior lecturer of Environmental Science and Technology, 8/16/22
How Our Team Reflected & Integrated:
UMaryland iGEM met with Jose-Luis Izursa, a senior lecturer of Environmental Science and Technologies at UMD. The topic of our discussion was bioreactors, biofilters, and nitrate remediation strategies. Dr. Izursa presented systems used in aquariums that consist of a biofilter system that is used to remove excess nutrients from the water. It is apparent that there are many parallels between the functions of these two systems, and this design served as a foundation for the Nitrate Neutralizer Bioremediation System. Components of the biofilters that Dr. Izursa presented to UMaryland iGEM were directly incorporated into the design of the NNBS.
Dr. David Ruppert, UMD College of Agriculture and Natural Resources, 8/29/22
How Our Team Reflected & Integrated:
The team met with Dr. David Ruppert, a faculty member at the UMD College of Agriculture and Natural Resources. Dr. Ruppert taught us about the dynamics of fertilizer runoff and leaching, as well as the need for technologies that reclaim and recycle nutrients. There is currently a lot of energy put into government programs and conservation organizations that is directed towards bioremediation and removal. However, if there were a system that allowed the farmer to reclaim their nutrients, it would be cost effective for the farmer and it would prevent nutrients from leaching into the Chesapeake Bay. On top of this, the process by which ammonia is synthesized for fertilizer use is immensely unsustainable. The carbon emissions and energy consumption that go towards this one commodity chemical are substantial, and demand for it could be drastically reduced by providing farmers with a way to reclaim their leached nutrients.
Ruth Cassily, Chesapeake Bay Agricultural Programs, 8/30/22
How Our Team Reflected & Integrated:
The team had a meeting with Ruth Cassily, a faculty member at the UMD College of Agriculture and Natural Sciences, as well as the Chesapeake Bay programs. The object of our meeting was Best Management Practices (BMP) for farmers and how new technologies can be incorporated into this. BMP is the set of guidelines that are farm-specific and economically feasible that are in place to minimize environmental and public health impact. This includes but is not limited to soil and water conservation, crop irrigation management, waste management, and nutrient management. BMP works in conjunction with Watershed Implementation Programs (WIPS), which are larger scale, government programs that are dedicated to improving the condition of the Chesapeake Bay Watershed. Ms. Cassily also explained that nutrient pollution does not runoff into the Chesapeake solely from Maryland farms, and that there are actually sizable pollution contributors from upstream states like NJ, DE, and PA. PA has the most agricultural landmass upstream of the Chesapeake, and over time, they have been the worst performer in terms of nutrient management. Insights from this conversation made it clear to our team that our system must be scalable. For this system to work within BMP and a WIP, this system must be feasible for a commercial factory farm in Maryland, as well as a small family farm in rural PA. This was incorporated directly into our Bioreactor Design. We made our system scalable in the sense that any farm can use the Nitrate Neutralizer Bioremediation System. The scalability of the bioreactor vessel and flow dynamics allow for this system to be used by various types of end user.
Sarah Lane, UMD Center for Environmental Sciences, 9/9/22
How Our Team Reflected & Integrated:
UMaryland iGEM met with Sarah Lane, a Senior Research Assistant at the UMD Center of Environmental Sciences. The focus of our meeting was implementation of new technologies and the ways that political forces impact adoption of technology. Ms. Lane taught us about WIPs and how the feasibility of a technology can be determined. The likelihood that our end user will want to use our technology is dependent upon how fiscally reasonable it is. Subsequently, there is a value of cost per pound of nitrates removed that represents this line of adoption or rejection ($800/pound nutrients removed/day). This line exists because a new technology has to be novel and effective, while also being low cost enough to compete with natural alternatives. These alternatives include current means of runoff mitigation like cover crops, Riparian buffer forests, and no-till farming. Ms. Lane also taught us about how WIPs have changed over time, how different states succeeded or failed, and what the components of a successful WIP are. This gave UMaryland iGEM a depth of knowledge as to what goes into an effective, user friendly technology. The takeaways from this meeting were directly implemented into our project as we set the budget of our Bioreactor System to be at $800/pounds nutrients removed/day.