Distilled Water

The analytical chemistry and industrial process engineering of water distillation involve phase-change thermodynamics to separate water molecules from dissolved ionic and organic contaminants. Distilled water (conductivity <1 µS/cm) differs fundamentally from filtered or reverse osmosis water in its near-total removal of dissolved solids, making it the standard for laboratory reagent preparation, pharmaceutical manufacturing, and specific industrial applications.

The Phase-Change Chemistry & Industrial Water Purification Science hub analyzes distillation at a molecular level. Core attributes include the Raoult’s Law basis for distillation (volatile water separates from non-volatile salts), the energy efficiency comparison between single-stage and multi-effect distillation (MED) systems, and the TDS (Total Dissolved Solids), conductivity, and resistivity specifications that define water purity grades (Type I, II, III per ASTM D1193). The technical value lies in matching water purity specification to application requirements.

Ion Exchange & Ultrapure Water Production

We examine how mixed-bed deionization (MB-DI) following distillation achieves Type I ultrapure water (18.2 MΩ·cm resistivity) by removing residual ions via cation and anion exchange resins. Our analytical guides focus on the TOC (Total Organic Carbon) limitation of ultrapure water systems and the critical importance of point-of-use filtration to prevent biofilm contamination. Understanding water chemistry ensures optimal performance in sensitive applications.

FAQ: Water Chemistry

Is distilled water safe to drink? It is not harmful, but it is also not optimal for regular consumption. The complete removal of minerals (calcium, magnesium, fluoride) means it provides no dietary mineral contribution. Some research suggests very low-mineral water may leach minerals from foods during cooking and may have a flat, slightly acidic taste due to dissolved COâ‚‚.
Why do CPAP machines and steam irons require distilled water? Tap water contains dissolved minerals that deposit as scale (calcium carbonate) when water evaporates in heating elements. In CPAPs, scale buildup damages humidifier chambers. In irons, scale clogs steam vents and can stain fabrics. Distilled water eliminates the mineral content that causes this.

Uses: Application Matrix.