Michelle (UR) - Persistence DOES pay off

So much for a disposable cup.

Weighing out alginate powder.

Alginate gel, mixed and ready to be dried.

After allowing my alginate mold to air dry for 7 days, there was a massive hole in the bottom. This made it useless as a disposable cup. However, I was not ready to give up. I decided to attempt my original idea again, this time using the alginate as a skimmer instead of a filter. After watching the alginate consistently dry with holes, I decided to lower my ratio of powder to water to 1:1. Using 6.0636g powder and 6mL distilled water, I mixed the gel and pressed it into a dish. I dried it in the Isotemp oven at 120°C for 15 minutes.

To prepare for the skimmer test, I filled a beaker with 300mL of water. Using sand that was known to contain microplastics, I mixed 3 scoops into the beaker and stirred it around a bit. I then used forceps to hold a piece of alginate gel, and skimmed it around the water.

If my hands hadn't been full, I'd have had my fingers crossed.

The organic material was stuck to the gel

After multiple failures, my hopes were not high. However, previous tests had resulted in alginate that was very strong once re-wet, so I did not expect the alginate to fall apart. When I removed the gel from the water, I could see organic material stuck to its surface. I placed the alginate in a dish and immediately looked under the microscope at it. The results were outstanding. Six pieces of microplastics were found on the first sample. After photographing each, I attempted to replicate the results using 2 other pieces of the gel. The results were spectacular. The least amount was 4 pieces, on the smallest sample.

Graph depicting the amounts of microplastics in each sample

Microplastics come in many different forms, and I found quite a few different shapes and sizes. Hopefully future research will scale up these tests, and attempt to use the alginate skimmer in different saline environments. If the alginate withstands salinity, it should be tested in the ocean and rivers to determine its strength in currents. I hope that my research project shows not only the potential for alginate as a solution to the problem of microplastics in our waterways, but also that you should never give up on your ideas. Just keep trying, no matter how crazy your idea seems.

A blue microfiber captured by the alginate skimmer.

A black microfiber captured by the alginate skimmer.

A piece of blue microplastic captured by the alginate skimmer.