I haven't seen anyone else write about this yet, so I am posting this just to stake my claim as the first one to mention it.  I think activated charcoal might be effective to adsorb the "novel coronavirus". There, I've said it. 

The rest of this is just a placeholder so that I'll remember to come back later and fill in the details. 

However, what I have confirmed so far is that activated charcoal / carbon has been shown to adsorb certain kinds of viruses. I'm not sure whether the so-called novel coronavirus fits into that category because I haven't been able to find out what kinds of viruses it does work on. 

I've also confirmed that activated charcoal / carbon has been used to adsorb oils. So perhaps it would attract the lipid bilayer of the novel coronavirus. 

I'll get back to this another day. Just wanted to stake my claim for having published this on May 8, 2020.