Brita, maker of popular water-purifying pitchers, will launch a recycling program for used water filters beginning in January. The company’s announcement comes after months of pressure from citizen activists. Consumers will be able to drop used filters off at selected Whole Foods stores or mail them in; the plastic parts will be turned into recycled toothbrushes and razors, and the activated carbon “will be regenerated for alternative use or converted into energy,” according to the company.