Intern Marc Porosoff spent a lot of time inside the
clean room collecting deionized water samples
Intern Marc Porosoff is a senior at Johns Hopkins, majoring in chemical engineering. NXP is a chip fab plant located on the IBM campus in Fishkill in the Hudson Valley. The facility requested an intern to evaluate the feasibility of recycling deionized water in its "clean room" manufacturing area where semiconductor wafers are polished with an abrasive slurry and rinsed with ultra-pure deionized water. The rinse water is constantly flowing to prevent bacteria growth, and the wafers are in a constantly flowing bath to remove all traces of slurry and minimize contamination. The water must meet high standards of purity. Mr. Porosoff designed a drain line manifold to route used deionized water for recycling. He studied impacts of a failure scenario on different analytes and determined that pH and resistivity would be the best indicators for the study. Many samples were collected and analyzed. Mr. Porosoff concluded that the deionized water could be recycled and the program should be implemented. Multiple sensors connected to automated drain valves in the treatment train provided a measure of safety. He estimated that 21 MG of water annually can be saved. Note that in addition to water conservation, 21 MG less deionized water will need to be generated, conserving 966,000 kWh of energy.