Plastic pollution and treatment (WPO + FE) questions

[RPinPA]

I am interested in plastic pollution, particularly microplastics (< 5 mm). This passage is taken from a NOAA document describing recommended methods for microplastic pollution measurement. This is for samples of sea water containing plastic.

"The sieved material is dried to determine the solids mass in the sample. The solids are subjected to wet peroxide oxidation (WPO) in the presence of a Fe(II) catalyst to digest labile organic matter. The plastic debris remains unaltered. The WPO mixture is subjected to density separation in NaCl(aq) to isolate the plastic debris through flotation. The floating solids are separated from the denser undigested mineral components using a density separator."

Several questions about this procedure:

1. What exactly does the WPO + FE(II) treatment do? What is included in that "labile organic matter"?

2. Is a "density separator" just a centrifuge?

3. Does this sound like something that it would be possible for non-specialists to set up, or should I look to partner with a chemist? I have a feeling I know what the answer to that is, but I'm looking to maximize what can be done at low cost.

4. Would that treatment separate food from plastic food containers? The reason I ask that is that government recycling programs typically ask you to wash off food, as I've heard that contaminates the recycling process, and I've always wondered why there isn't some simple chemical or biological method for removing the food particles. Why is food contamination such a problem?

 

 

UPDATE: Later in the article I think I found the answer to #3-4.

"CAUTION: This mixture is highly reactive. Please review and follow your laboratory safety practices and policies for handling this mixture before completing this analysis."

Still makes me wonder whether it is a potential solution for contamination of commercial recycling.

Edited October 26, 2018 by RPinPA