DISTILLED WATER: THE UNIVERSAL SOLVENT FOR PRECISION APPLICATIONS

Distilled water (H₂O) is ultra-purified through vaporization and condensation, removing >99.9% of dissolved solids, minerals, and microorganisms. With global consumption exceeding 50 billion liters annually, this benchmark purity standard serves critical roles in laboratories, pharmaceuticals, automotive systems, and medical applications where ionic contamination must be minimized.

Key Specifications & Production

Physical/Chemical Properties

• Conductivity: 0.5-5 μS/cm (vs. 50-500 for tap water)
• TDS: <1 ppm (EPA/ISO standards)
• pH: 5.0-6.5 (due to CO₂ absorption)
• Resistivity: 1-18 MΩ·cm (Type I/II)

Production Methods

Quality Standards

Critical Applications

1. Laboratory & Pharmaceutical (40% Usage)

• HPLC Mobile Phases:
  • Prevents column contamination
  • Requires <1 ppb heavy metals
• Cell Culture Media:
  • USP WFI (Water for Injection) standards
  • Pyrogen-free processing

2. Industrial Processes

• Lead-Acid Batteries:
  • 5-10L/kWh battery capacity
  • Prevents sulfation (Ca²⁺ <0.5 ppm)
• Humidification Systems:
  • Avoids mineral scaling

3. Medical & Healthcare

• Sterile Irrigation:
  • USP purified water standard
  • 0.2μm filtered
• CPAP Machines:
  • Prevents mineral deposits

4. Automotive

• Coolant Dilution:
  • 1:1 with ethylene glycol
  • Prevents electrolytic corrosion
• Battery Top-Up:
  • Maintains specific gravity

Performance Comparison

Storage & Handling

✅ Best Practices:

• Containers:
  • Polyethylene/Teflon (avoid glass leaching)
• Preservation:
  • Nitrogen blanketing prevents CO₂ absorption
• Shelf Life:
  • 24 hours (open), 6 months (sealed)

⚠ Contamination Risks:

• Airborne CO₂: Lowers pH to ~5.7
• Plasticizers: From HDPE containers
• Biofilm: In stagnant systems

Market Insights

Production Capacity

• Industrial Scale:
  • 10,000+ L/hr systems (power plants)
• Laboratory Scale:
  • 4-20 L/hr quartz stills

Price Factors

• Pharma Grade: $0.50-2.00/L
• Technical Grade: $0.10-0.30/L
• Bulk Industrial: $0.05-0.15/L

Emerging Trends

• Point-of-Use Generation:
  • Compact vapor compression units
• Renewable Distillation:
  • Solar-powered stills

Conclusion

Distilled water remains the gold standard for purity-demanding applications where even trace ions could compromise processes. While reverse osmosis and deionization compete for some uses, distillation’s absolute particulate removal and sterility ensure its continued dominance in critical scientific, medical, and industrial applications.