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Yidian Liu: Developing Systems for Mitigating Aquatic Microplastic Pollution

Yidian Liu: Developing Systems for Mitigating Aquatic Microplastic Pollution


Ladderworks is a publishing platform of diverse picture books and online curriculum with the mission to empower over a million kids to become social entrepreneurs. Our current series features interviews by our interplanetary journalist Spiffy with inspiring Social Entrepreneurs, Entrepreneurship Ecosystem Builders, and Changemakers who are advancing the UN SDGs.

Spiffy here! I’m back with the scoop on the entrepreneurial leaders of Planet Earth. As the only interplanetary journalist stationed on this blue planet, I’m thrilled to present this galactic exclusive with Yidian Liu, the co-founder of PolyGone Systems. Let’s see what she is doing to make a positive impact in the world.

Spiffy: It’s wonderful to meet you, Yidian. I’m curious about the challenges PolyGone Systems is addressing. What can you tell me?

Yidian: It’s great to be here, Spiffy! The pervasive issue of aquatic plastic pollution, with millions of tons of plastic waste entering our oceans annually, has garnered worldwide concern. These plastics degrade into microplastic fragments, posing a significant threat to marine life and humans. Microplastics, measuring less than five millimeters in diameter, disperse widely across vast geographical areas, making their collection an arduous task.

Spiffy: That’s indeed a great problem to solve! What motivates you to do it?

Yidian: My co-founder, Nathaniel Banks, and I started investigating this issue during our joint thesis project on aquatic plastic pollution and waste infrastructure at Princeton University. We were shocked that there were no systems for mitigating the microplastic pollution in our waters. In response to this revelation, we have developed a modular floating device called the “Plastic Hunter,” with attachments of our proprietary filter, the “Artificial Root.” This microplastic filtration device operates effectively in polluted rivers, reservoirs, and wastewater effluents. After graduation, we founded PolyGone Systems with the aspiration of transforming the innovation into a sustainable business.

Spiffy: More power to you! What is the impact of your work?

Yidian: In 2019, 109 million tons of plastic accumulated in rivers, and subsequently, 1.7 million tons were transported from rivers to oceans. By targeting high-emission rivers, where approximately 80% of annual plastic emissions into the oceans occur, our team is ambitious of capturing hundreds of millions of microplastics before they reach oceanic systems. 

Spiffy: That’s amazing! Tell me about a recent organizational milestone or initiative. What impact does that make?

Yidian: Our team at PolyGone is partnering with the Atlantic County Utility Authority (ACUA) and will be building a pilot project with our microplastic filtration system, the Artificial Root filter, at ACUA’s existing water treatment facility. This would be the first microplastic filtration system built into a wastewater treatment plant in the United States. With this pilot, we aim to effectively capture aquatic pollutants and microplastic debris within the wastewater that flows through ACUA’s main pipeline, where it receives around 40 million gallons of wastewater per day from 14 municipalities in Atlantic County. This means over 270,000 residents will be impacted by the improvements.

Spiffy: Is there anything else you would love to tell our audience?

Yidian: When Nathaniel and I first investigated the problem, we were told by all of our advisors at Princeton that our thesis idea was a waste of time to pursue. Since we were targeting microplastic filtration technology and only had design backgrounds, they did not believe we had the expertise to develop the idea and suggested that we give up. However, we were stubborn because we had a passion for addressing this issue, so we played to our strengths with design and brought on scientists from the chemistry and environmental science departments to help advise us on the development of our very first minimum viable product (MVP), which became the foundation of PolyGone.

Spiffy: Thanks for speaking with me today, Yidian—it’s been an honor!

Yidian Liu is the co-founder and COO of PolyGone Systems. She holds a bachelor’s degree in architecture from Syracuse University and a master’s degree in architecture from Princeton University. (Nominated by Unshackled Ventures. First published on the Ladderworks website on October 3, 2023.)

The views and opinions expressed herein are those of the interviewee and do not necessarily reflect those of Ladderworks LLC.

© 2023 Ladderworks LLC. Edited by Sujit Kunte. Spiffy’s illustration by Shreyas Navare. For the Ladderworks digital curriculum to help K-3 kids advance the UN SDGs, visit Spiffy's Launchpad: Creative Entrepreneurship Workshops for K-3 Kids and their caregivers here.