Interviews with Experts

Dr. Diane Evans - Professor at Rose-Hulman Institute of Technology

Diane Evans, Ph.D teaches the six-sigma classes here at Rose-Hulman. She has been teaching this class for seven years and is certified with her black belt. Six-sigma is a class that collects real world data and then implements a change that has a positive influence on world problems. In the past, the six-sigma classes have taken data on food waste in the cafeteria, recycling, and food sharing programs. The most recent class chose to do a project where they recorded data on plastic straw usage. As part of the educational outreach, Dr. Evans asked Dr. Shikha Bhattacharyya to come to Rose and talk about the impacts of plastic straws on the environment. This movement made a huge impact on the school as a whole, and was one of the motivations to picking our project this year.

To find out more about her biodegradable straw project watch the video below:

We also asked Dr. Evans what she thought about our project and the possible implementation methods we brainstormed. See the diagrams below to read details on the implementation methods we came up with and watch the video below to find out her thoughts:

Dr. Jared Tatum - Plastic Specialist at Ampacet

Dr. Jared Tatum is a chemical engineer who works with PET plastic at Ampacet. He explained that in the manufacturing process, pure plastics are typically mixed with other materials in order to make them as cheap as possible. Materials such as metals can be added so that the plastic can be stretched to be as thin as possible. Other chemicals can also be mixed in to give the plastic a clear and shiny appearance, so the product is more appealing to the consumer. He also explained how PET plastic is initiated as a single strand that twists on itself as the chain lengthens, creating the molten mass that can be shaped. His information about the generation of plastic was very useful, and he provided PET samples for our lab work.

Susan Reynolds - Facilities Manager at Rose-Hulman

Ms. Reynolds talked to us about the level of recycling at Rose-Hulman and the variety of initiatives taken over the past 22 years. Initially, the campus had several home-sized recycling bins at the back of one building and only took PET plastic, paper, cardboard, tin, aluminum, and E-scraps. The paper and cardboard were sold, while the other recycled products were sent to Indiana State University’s recycling facilities. The demand grew enough for Rose-Hulman to develop the current center with 3 compactors and multiple recycling drop offs per week. Currently, Rose has received grants and works with Republic recycling company to manage the recycling. A report she gave us indicated a total of 48 tons of cardboard, 6 tons of paper, and 27 tons of scrap metal recycled in 2015. While impressive, Rose can still improve as there was still over 400 tons of trash generated that year, which was equivalent to 2552 cubic yards. She has been very receptive to the student driven initiatives to improve better signage and convenience. Understanding what Rose’s campus has done to help the plastic waste build up and their initiatives has helped us target our implementation methods and has informed the background of our project.

Elizabeth Attebery - Supervisor, Recycle/Waste Management/Moving & Set-Up at Indiana State University

Ms. Attebery gave us a tour of the Indiana State University’s recycling center. She explained the recycling processes at the center and showed us the corresponding machines. For plastic recycling, the center takes plastics #1-7 and put them on a conveyor belt. They sort out any non-plastics, and the rest falls into a large container. The container is wheeled over to a baler, and the plastic is shoveled out and pressed into large bales. These bales are stacked outside until they are shipped to be further processed. The recycling center is not only for the students at the school, but it has a drive-thru for the community to drop off recycling. We visited ISU as part of our interest in analyzing if it could be better to have our bacteria working at recycling plants before the waste even gets into the ocean, or if it could be better to work on cleaning up the waste already in the ocean.

Implementation Methods Survey

As our team considered different implementation methods, we brainstormed ideas and chose 3 to be most feasible.

Method 1 directly addresses the issue of plastic waste in the ocean, because it involves deploying small vessels to follow the ocean currents and filter the surface water for floating plastic and microplastics. The sea water would filter through the base of the vessel through a screen infused with the PEBBLE bacteria. Any plastics would be caught on the mesh and be degraded by the bacteria. The mesh would also theoretically collect and store the terephthalic acid byproduct until the vessel is picked up for maintenance. The collected acid would then be removed and shipped to the industries that need it, while the vessel culture would be diluted and sent back out. This method would need government-level support and would also be a standardized collection method for TPA.

Method 2 institutionalizes bioreactor tanks of the modified E.coli at major waste and recycling collection facilities. The bacteria in the reactors would filter out the PET plastic and breakdown the polymer into terephthalic acid and ethylene glycol, a carbon source for the cells’ metabolisms. The acid would be syphoned off and sent to plastic industries to be used in the creation of additional plastics. The material not degraded would be sanitized and moved on to the next stages in the waste disposal process. This method would be a community and local government/business commitment and would address the waste generated on land.

To make an impact on the individual-level, we came up with Method 3 where home kits would degrade the PET plastic before it was sent to collection facilities. These kits would be equipped with a receptacle for the bacteria to be housed, and the plastic would be fed through a system which prevented the user from coming in contact with the bacteria. The terephthalic acid would be syphoned off and the user could bring it to a collection facility for the plastic industry and potentially receive monetary compensation. This reward would act as an incentive for users to put the plastics in the compost kit. The material not degraded could then be sanitiatized, packaged, and taken to the local recycling or waste collection facilities. Method 3 addresses the source of the waste generation at the very beginning of the process and provides an incentive for people to recycle.

Having designed three methods from our own backgrounds, we wanted to reach out to the community to gauge their receptiveness to each method and understand their concerns about the growing plastic waste. In the survey, we present the three possible implementation methods of our project and ask about the public's concerns with each of our methods. We reached out to experts and willing volunteers for help with the design and piloting of the survey. We ask the final career question to gather an idea about the relative age groups of our populations.
Our survey was approved by Rose-Hulman's institutional review board (IRB). See the letter of approval here.

Administration Strategy

We created a google form with the approved survey questions and distributed via:

• social media
• campus newsposts
• emails to experts and contacts

We also printed off paper surveys and distributed via:

• approaching both students and employees on campus about filling out the survey

In each method, people were encouraged to share the link to distribute the sampling beyond our own circles. Our administration strategy has been mostly convenience sampling since most participants have a connection to one of us, but we are working hard to minimize that and get more random sampling by encouraging relatives to share the survey with their coworkers and friends.

Initial Hypothesis

We believed that most people would be at least somewhat familiar with recycling methods, but reluctant about using genetically modified organisms for recycling. We also expected the most acceptable method for the public would be method 2 with the PEBBLE bioreactors at landfills and recycling plants.

Survey Results and Changes

The survey data allowed our team to redesign our implementation method to address the preferences and concerns from the sampled public. Due to the range of backgrounds in the respondents, this survey could not draw conclusions on views of a specific population. However, we did determine from the background questions that the survey’s respondents were moderately familiar with recycling, and considered the current methods of recycling insufficient for plastic waste demand. There was no significant correlation between the respondents' method choice and their level of comfort with genetically engineered bacteria. There was a statistically significant correlation between occupational status and respondents’ preference of method. Our initial hypothesis was correct in assuming Method 2 would be the most preferred and we modified it to address the voiced concerns of the respondents. The final implementation method would involve our team implementing bioreactors at PET manufacturing plants. The recycling centers would sort and transport their plastic to these sites and the rejected products of manufactures would be placed in the bioreactors for the engineered bacteria to degrade. At these plants, the personnel would already be trained and have procedures in place for dealing with the plastic and its byproducts. These sites would already have appropriate waste water treatment for effluents from the bioreactors, and the manufacturers would benefit from being more environmentally friendly and taking responsibility for their product throughout its life cycle. This plan addresses the top concerns about personnel training and byproduct exposure. This method appears to be feasible from our investigation at the local recycling center because they, along with many other sites, already sort and ship the plastics to different facilities. From the survey responses, this revised method would alleviate many concerns and improve their preferred choice of implementation for the PET degrading bacteria. The following is a full report and analysis on the community survey.

References:

• [1] “How it works.” Ocean Clean Up founded by Bolan Slat. 2018. [Online]. https://www.theoceancleanup.com/technology/
• [2] D. Reid, “A self-made billionaire is giving away his fortune to clean up the oceans,” CNBC Make it. May 2017. [Online]. https://www.cnbc.com/2017/05/18/a-billionaire-is-giving-his-fortune-away-to-clean-up-oceans.html