Lanxess is doubling capacity at its reverse-osmosis membrane plant in Bitterfeld, Germany. Lanxess entered the reverse-osmosis membrane business only five years ago, and already, the company says, capacity at its plant has nearly sold out. The market for the products, used in water treatment, is growing at a 10% annual rate, the company says. Lanxess expects the new capacity to be on-line during the second half of next year. Over the past five years, Lanxess has invested $45 million in the Bitterfeld reverse-osmosis membrane plant.