Science Buddies: "Ask an Expert"

Hi, I’m working on a science research project about biochar adsorption of microplastics. Im working with a mixture of microplastics bound to biochar, free biochar, and free microplastics. Does anyone know of a way to determine quantitatively how much of each component would be in a mixture. Alternatively, does anyone know how I would separate the components of this mixture?

One idea is to use a flow through system like a water filter to trap the biochar, and let water solution containing microplastic to flow through it. You will need to find a way to measure the microplastic concentration before and after the flow through, and have a filter with no biochar as a control.

Quantitatively characterizing the amount, size, type, etc. of microplastics in your samples will be difficult without some specialized infrared spectroscopy equipment (e.g., Fourier transform infrared (FTIR) spectroscopy). Here's an article that goes through a few possible approaches, under the Methods of Detection section: https://link.springer.com/article/10.10 ... 21-12943-5. I also found this document titled "A Citizen Science Approach to Measuring Microplastics in Berlin's Water:" https://digital.wpi.edu/downloads/h415pd439. This latter document is extremely thorough and is intended for getting the public involved in science, so it should have some good ideas for your project that don't require fancy equipment.

If you want to separate your components, you should check out the literature on microplastic separation in wastewater treatment facilities. There are many different processes these facilities can use to substantially reduce the amount of microplastics in treated water. You could probably make a biofilter at home without much trouble.