Effect of component interactions on the removal of organic impurities in ultrapure water systems

The interaction among the components of the ultrapure water systems in semiconductor plants is explored. Two important examples of these interactions are investigated: interactions of ultraviolet (UV) radiation units with membrane filters and interactions of UV with ion-exchange units. Both experimental and theoretical techniques are developed to study these interactions. The results indicate that the sequencing of UV and filter units affect the efficiency of total oxidizable carbon (TOC) removal. In particular, the efficiency is higher when the filter is before UV. Interaction between UV and ion exchange is desirable for the removal of recalcitrant, low-molecular-weight organic compounds such as ethanol, but undesirable for the removal of high-molecular-weight charged compounds such as bacterial lipopolysaccharides, alginic acids, humic acids, methionine, and glycine