6th April 2012 at 1:49 pm #778
Just a note…don’t confuse “charcoal” with “activated carbon.” Charcoal can be the products of burning at just about any condition and does not necessarily have a lot of capacity to take up water-born contaminants. Activated carbon, used in what are sometimes called “charcoal filters,” is organic matter from a variety of sources which is oven-treated with a controlled temperature and gaseous environment to make it porous at a microscopic level. The huge internal area, like a molecular sponge, is what makes the activated carbon work well. A teaspoon of activated carbon actually has internal surface area equal to the size of a football field, and it can all be used to hold contaminants that get into the pores.
So the question is, can this kind of carbon be made easily in a developing world facility? Or, is there any kind of charcoal from open fires that has this kind of capacity? It is not likely. The activation is actually a highly controlled two or three stage process, and it also requires either the addition of a synthetic chemical or direct injection of CO2 or O2 during the activation firing. Charcoal that is not activated by such a process will still take up some contaminants, but it will not last very long because its capacity is lower and will be used up. Perhaps there is a way to do an activation process in a low-tech facility that may not provide the highest capacity but will be good enough – that would be a good research project (or maybe it has been done, sometime and somewhere, over the century of activated carbon’s development). The other issue is getting people to replace carbon in a filter and how they even know when this is necessary.
Steve Dentel