MIT researchers found that a small chunk of Eastern White Pine branch can effectively filter E. coli bacteria and probably most viruses from water.
MIT press release, PLOS One journal article.
Except:
- You can produce only 4 liters per day, i.e. filtering 1 liter takes 6 hours.
- You need 5 psi of pressure to get that flow, equivalent to 3.5 meters (11.5 feet) of gravity head.
- They ran only a few milliliters of water through the branch, who knows if you can really get 4 liters per day.
- You can’t let the branch dry out, or it stops working.
- They tested only Pinus strobus, and they are pretty sure it won’t work with hardwoods.
Bottom line: Don’t depend on filtering your water through a tree branch any time soon.
— Rex
