Plastic waste breaks down over time into nanoplastics (<0.1 μm). Microplastics smaller than 20 μm cannot be removed in currently operating water treatment plants and must be agglomerated to a larger size and then removed. Iron (Fe) or aluminum (Al) based flocculants are used for this purpose, but they are not the ultimate solution as they remain in the water and cause severe toxicity to humans, requiring a separate treatment process.

Dr. Jae-Woo Choi of the Center for Water Cycle Research at the Korea Institute of Science and Technology (KIST) has developed an eco-friendly metal-organic skeleton-based solid flocculant that can effectively aggregate nanoplastics under visible light irradiation. The research was published in Water Research.