91色情片

Nutshells discarded by the food industry could help soak up metal-based
pollutants from water. Traditionally, coal has been the source of 鈥渁ctivated鈥�
carbon鈥攁 substance so minutely holed that its high effective surface area
lets it absorb other chemicals. Now, researchers with the US Agricultural
Research Service have developed a process that activates the carbon in cheap
waste nutshells, and renders it more efficient than expensive coal-derived
carbon. Phosphoric acid eats into the shells and increases their surface
area.