Kentucky lawmakers discuss efforts to remove microplastics from water

FRANKFORT, Ky. — Kentucky is a leader in the bourbon and horse industries and could become a national leader in developing strategies to control microplastic waste, lawmakers heard Thursday. Sen. Brandon Smith, R-Hazard, said the issue of microplastics is expected to receive increasing attention. Smith and other members of the Interim Joint Committee on Natural Resources and Energy heard testimony about efforts to address the waste. 'It's going to become a very big thing, and one of the reasons Kentucky is looking into it is because we're really leading the way,' Smith said. 'We were one of the first states to file a piece of legislation to help direct it and get some ideas and boundaries for it. It is certainly not going to go away.' Jian Shi, a professor in the Department of Biosystems and Agricultural Engineering at the University of Kentucky's Martin-Gatton College of Agriculture, testified about research under way at UK to remove microplastics from water using a specialized solvent. Shi said microplastics are a global issue because they can move through water, rain and rivers to various locations, including into the human body. 'The particle size of plastics, when it becomes smaller, it becomes even more challenging because it's hard to take out from the water,' Shi said. Filtration and centrifugation become inefficient or expensive when particles are extremely small, he said. Larger pieces of plastic are easier to capture, while microplastics are more difficult and nanoplastics are extremely difficult to remove. Shi said green solvent extraction uses a liquid solvent that is effective and readily available from plant-derived ingredients. One method involves suspending plastic particles in water, adding the green solvent and mixing the liquids. The plastic eventually moves from the water into the solvent. Microplastics and nanoplastics are concerning for ecosystems and human health because the particles can be found in tap water, bottled water and food, Shi said. 'This has been a concern from the scientific community because it's possible microplastic or nanoplastic particles will get carried through small living things and to fish and to crab and eventually go to human bodies,' he said. Shi said the particles can also enter wastewater treatment plants and eventually make their way into tap water. Rep. John Blanton, R-Salyersville, asked Shi when green solvents could be used to remove plastics. Shi said he believes the process most likely would be applied at wastewater treatment plants initially. Blanton said that when he first heard about microplastics, he thought of water bottles. He also noted that many homes and water systems use plastic pipes to transport water. Shi said most microplastics originate with discarded items that enter waste streams. Some eventually reach water and soil, where the plastic breaks down into smaller particles. Polyvinyl chloride pipes also can be a source of microplastics, he said. Rep. Adam Moore, D-Lexington, asked Shi about the performance of lignin-based hydrophobic deep eutectic solvents, or HDES, in removing the particles. Shi said the method can achieve a high removal efficiency. 'It's a very active research area now, looking to different ways of removing those micro- and nanoplastics from the water,' Shi said. 'The method I showed you is one-step removal, which is 95%. If you want to shoot for higher removal, it's likely going to be multi-stage, the separation process.' Smith said people are questioning not only how prevalent the particles are in human bodies, but also how industries are considering the costs and potential regulations. 'We've seen a lot of pop-up companies saying that they can do this in large scale, and I'm very skeptical because this stuff is extremely slippery,' Smith said. 'And it's everywhere and that's something about it. You can be someone who's been very, very cautious and watch what you've eaten and you still are going to have probably as much of it as I do because it's in so many things that we touch every day.'