Virtual Lab Tour

A step-by-step walk through of how plastic researchers learn about microplastics in rivers, from field samples to lab work to write-up.

Virtual_tour_MeasuringMicroplastics_process_visuals

Explanations, by slide number:

  1. Contact me, Lisa Watkins, if you end up using this presentation for your group!
    Made Spring 2021 based on research method for sampling microplastics in rivers, as developed & followed by members of the Soil & Water Lab in the Department of Biological & Environmental Engineering at Cornell University (http://soilandwater.bee.cornell.edu/).

  2. A HUGE net (because compared to water, microplastics are scarce, especially in rivers)

  3. We let the water (& sticks & flower petals & sand & plastics) flow into and through the net for 10 minutes.

{this is Six Mile Creek in Ithaca, NY}

  1. Everything gets collected into the very end of the net, which (conveniently) we can unscrew and take with us back to the lab. (See picture of Kenji, on the left)

In the lab, we rinse everything that was collected into that tiny bag into a beaker (like Susan is doing in this picture)

{Our lab is in the basement of Riley Robb Hall on Cornell University campus}

  1. This is the stuff that gets caught in the net during that 10 minute period. (looks & smells kind of like poop since it’s mostly just rotting, soggy organic material). Since microplastics are any plastic smaller than 5mm, we only keep the small stuff (and get rid of any big sticks or rocks or leaves)

  2. Then we add hydrogen peroxide (along with Sulfuric Acid, which acts as a catalyst, making the reaction happen faster). In the same way hydrogen peroxide stings and bubbles on a cut as it eats away all the bacteria and dirt in a wound, it bubbles and eats away at all the leaves and other organic material in our sample, leaving behind the plastic (and sand & bits of hard wood & other hard-to-digest items).

  3. Here’s a video of what it looks like when we add the hydrogen peroxide to the river sample

  4. Once everything’s been digested, we separate heavy things left in the sample, like sand & grit, from the light plastics by letting them sit overnight in these funnels. (It looks yellow because we add a whole bunch of salt to it at this point too in order to make sure even plastics that are more dense than water won’t sink). Everything that sinks is discarded. Everything that floats is kept in the sample.

  5. We look at what is left over under a microscope (like Anna-Katherina is doing in this photo).

Here’s what she sees when she looks through the microscope--seed cases from plants that were too tough to be eaten all the way by the hydrogen peroxide and a few pieces of plastic. Looks like a blue fiber, a green fragment, a white piece of foam and another light blue fragment of some kind.

  1. Because it’s sometimes hard to tell whether something that looks like plastic is actually plastic (like is a fiber made of cotton or is it made of white plastic?), we use a super fancy microscope. It shoots a green light at each particle and the light bounces back off. Based on how it bounces off (is it shiny or not?), we can tell if the item is plastic (this is how some recycling facilities work, too!)

{The microscope + laser system is called Raman Microscopy. Our Raman process happens in the sub-basement of Bard Hall in the Engineering Quad at Cornell University}

  1. Once we’ve counted the plastics in that sample and tons more like it, we spend the majority of our time at a computer, seeing if we notice patterns in the number of plastics we counted. Then we present the patterns we noticed to other scientists who tell us what they agree and disagree with and we make changes based on their ideas. Then, thanks to their help, when we and the other scientists (who are anonymous) agree, we publish the research for other people to read and learn from.