Reverse Osmosis

Description

  • Use pressure to push water molecules from a wastewater solution through a semi-permeable membrane. Results in two streams: (1) water concentrated with chemicals (2) fairly pure water
  • See a presentation about the how reverse osmosis works (link)

Advantages

  • Consumes little energy
  • Operates at ambient temperatures
  • The clean water (permeate) may be pure enough to reuse for rinse water
  • Generally has a low initial and operating costs, compared to other technologies
  • Recover process chemicals for plating bath
    • May not be possible, depending on process and concentration levels
    • Contaminates will not be removed

Limitations

  • Membrane can be fouled by suspended solids
  • Membranes typically have a short life-span
  • System operates at a high pressure
  • Concentrated stream typically is not concentrated enough to return to the process bath
  • Impurities are not purged from the system

Implementation Process

  • Determine cost effectiveness in your process
  • Purchase and install equipment
  • Develop maintenance schedule
  • Train employees for use and maintenance

Resources

  • National Metal Finishing Strategic Goals Program
  • Metal Finishing, 67th Guide book and Directory Issue, January 1999, Volume 97, Number 1, 660.

Vendors