Proposed Implementation

Proposed solution

Our project focuses on the detection and degradation of PCBs, which pollute major water sources across the United States and the world.

We focused on two potential methods of implementation

1. release of genetically engineered bacteria into waterways
2. treatment in a bioreactor which would bioluminesce in the presence of PCBs and then break them down into less harmful products

Proposed end users

The organism to break down PCBs would be used by government agencies. These city and state agencies would release them into waterways, such as the Chesapeake Bay and the Hudson River. These waterways are contaminated with PCBs, and the organism would break down PCBs and remove the threat to the public’s health. Currently, it is very expensive to detect PCBs in a sample of water, and not many people have access to the equipment needed to do so. The current methods of PCB degradation, primarily incineration, are not sustainable, and our project aims to help users find a safer, more efficient way to break down these toxins. Our hope is that others would be able to use our project to clean polluted waterways near them at the commercial and the individual level.

These users could also use a bioreactor to contain the biosensor and the bacteria used to degrade PCBs. A bioreactor is a device that mimics an environment that can grow biological materials at an exponential rate. We researched which factors could be important to growing our organisms, including water flow, light levels, and nutrients. Using a bioreactor first allows us to make sure that our project is safe before introducing it to an open environment and it allows us to grow large quantities. Our proposed end users for the bioreactor implementation include government entities such as municipal wastewater treatment plants, and individual users near waterways who are looking for more affordable and effective ways to detect and degrade PCBs. The bacteria would be contained within an enclosed system and provided with nutrients in batches internally, which would limit its growth and allow us to model its efficacy. We would need sensors to monitor light levels, temperature, dissolved oxygen, and pH. These would allow us to track the health and progress of our bacteria. We would also have an agitation device such as a stirrer to catalyze the reaction.

Implementation in the real world: Release into waterways

We considered the practical environmental applications of our project to do our best to ensure that the final product would not harm any humans or the environment. The implementation team was responsible for understanding the EPA regulations surrounding PCBs and exploring ways to circumvent unintended side effects of practically implementing our genetically engineered system.We began by researching all EPA regulations on the disposal and destruction of PCBs [1]. We began our research by reading EPA regulations on the disposal and destruction of PCBs. This included legal documents explaining all of the factors required in introducing a new method to treat PCBs. We arranged a meeting with the EPA’s regional director for Maryland, Delaware, Virginia, and West Virginia in order to address our remaining questions and obtain a clearer picture of our pathway. We continued by building a slideshow to outline our written application and real-life implementation (the full process will take about 5 years) and creating a detailed outline of the process (PDF below).

Implementation in the real world: Bioreactor

Our project would likely need to be implemented in a separate bioreactor system that diverts water through it rather than directly putting it into the water. This would allow us to avoid the potentially negative consequences of introducing new bacteria into waterways. It would require people to monitor it and make sure that the reactor itself is safe and these people would require specialized handling training. We collaborated with the Math Modeling and the Human Practices subteams to further an idea of using a bioreactor, which would be a great way to avoid harming the ecosystem with bacterial release.

Other safety aspects and considerations

Aroclor is the most common trade name for PCB mixtures. There are many types; the suffix number (such as Aroclor 1260) indicates the degree of chlorination. The first 2 digits refer to the number of carbon atoms in the phenyl rings and the second 2 digits indicate percent chlorination by mass.

PCBs have significant toxic effects and exposure to them can cause various health effects as shown in their Safety Data Sheet [2]. PCBs are irritating to mucous membranes. When burned, PCBs produce highly toxic polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Even with low-level exposure, PCBs can be absorbed through skin, inhalation, and ingestion. Acute PCB exposure may cause skin, eye, nose, and throat irritation, while chronic exposure may cause chloracne. PCBs themselves are hazardous carcinogens to humans and other animals and can damage organs. PCBs take a long period of time to break down; they can bind to soil, dissolve in water, or be carried through air. PCBs can be absorbed by small organisms, like fish, through their environments, causing bioaccumulation in organisms as it travels up the food chain. They are carcinogenic to animals and can cause damage to their immune, reproductive, nervous, and endocrine systems. Although our biosensor/pathway for degradation has not been created yet/our project has not been completely outlined, when our project is released into rivers/environments (theoretical implementation), we will make sure that it only ameliorates the lifestyle of wildlife/humans and does not disrupt ecosystems as is required by the EPA regulations that we reviewed.

In addition, there are also safety issues when implementing in a bioreactor. Our intake water will contain a mixture of PCBs before they are filtered out, and PCBs cause known health problems. Accidental release resulting from any breach in containment measures can have adverse effects on the environment. Human health and safety hazards can be caused by exposure from inhalation, ingestion, and skin absorption. For example, if gloves or goggles break during work with PCBs, skin contact can result in these hazards.Therefore, our intake pathways would need to be protected and all operators would need specialized safety equipment.

Application for EPA approval

Because our proposed release of genetically engineered bacteria into waterways would heavily impact the environment, and even our bioreactor solution is subject to potential accidental release, we reached out to our local EPA representatives to learn more about the approval process for this. We spent a significant amount of time thinking about the EPA approval process, outlining that process for ourselves and other teams, and starting on the application itself. Here are the steps we learned and followed throughout the design of our solution:

Download Implementation Process Presentation

1. Present information about you and your project
2. List the people in your organization and their roles
3. Describe the pollutant you are treating
4. Describe all of the methods and and materials you plan to use
5. Prove the solution is efficient and safe
6. Describe the process of collecting and analyzing data
7. Report all possible reactants, products, and byproducts
8. Present a prototype for inspection
9. Compile emergency safety protocols
10. Create procedures for operation
11. Describe how the products will be disposed

We kept all of these steps in mind while designing our project so that it could be more viable as a real-world solution to PCB contamination. We hope that this information will be helpful to other teams focused on environmental issues in the future.

Implementation Process Outline

We compiled and synthesized our work with members of the EPA by creating a detailed outline of implementation processes and considerations in hopes that it may help future teams design their lab work with implementation in mind, especially when working with the EPA or similar governement agencies.

Download Implementation Process Outline

References

[1] Environmental Protection Agency. (2019, October 4). Guidance for Applicants Requesting to Treat/Dispose of PCBs Using Incineration or an Alternative Method. Regulations.gov. Retrieved October 13, 2022, from https://www.regulations.gov/document/EPA-HQ-OLEM-2018-0305-0010

[2] Sigma Aldrich. (2021, May 25). Safety Data Sheet version 6 . Retrieved October 14, 2022, from https://www.sigmaaldrich.com/US/en/sds/sial/459836