Book 30, Question 112
How does a charcoal filter pitcher work?
Inside a filter pitcher is a cartridge of activated charcoal, which has been treated to be full of tiny pores.
As water passes through, many chemicals and bad tastes stick to the huge surface inside the charcoal, like crumbs on a sponge. This is called adsorption. The charcoal can't hold forever, so cartridges must be replaced on schedule.