I wasn't sure where to put this discussion. I did a search on
water pasteurization, and it seems there is very little information beyond a few discussions on using
solar heat for this purpose.
I wanted to point out that it's possible to pasteurize water very efficiently by setting up a counterflow heat exchanger to preheat the cool unpasteurized water with the hot pasteurized water leaving the heater. It's a solution that many people seem to miss that can increase yields 5 fold or more. My calculations show that 1 pound of dry biomass burned in a small efficient furnace such as a rocket furnace or updraft gasifier furnace can easily pasteurize 20 gallons of water. Many sources of otherwise wasted heat can be used for this purpose as well. For example, use the exhaust from a
wood stove, or use the heat given off a stationary generator during operation. This principle could also be applied to a
solar water heating system to increase the yield of pasteurized water many fold. Also, note that this process can be used not only to pasteurize water from a nearby body of fresh water, but also used to process water taken from very shallow
wells that would otherwise not be potable. Finally, passing the pasteurized water through a simple filter system such as sterilized sand followed by crushed charcoal
should make for good quality potable water.
Again, it's a simple solution, but we often miss the obvious.