Effect of system interactions on the removal of TOC from DI water polishing loops

Ultrapure water systems in semiconductor plants consist of many components. The purpose is to explore the interactions of these units when they are placed in series and the effect of sequencing of these units and to establish conditions where these techniques can be used in combination. Two examples of these interactions are studied: UV interactions with membrane filters and UV interactions with the ion exchange units. An ultraviolet sterilization unit (Aquafine SL-1-TOC) generated radiation at both 185 nm and 254 nm wavelengths. The results indicate that the sequencing of UV and filter affects the TOC removal efficiency and that it is preferable to have a filter before UV. UV followed by ion exchange is an effective configuration for some impurities but can be undesirable for some contaminants and particles