Reverse osmosis

{
  "id": "MLC-T-ENV-024251",
  "term": "Reverse osmosis",
  "field": "Environment",
  "term_source": "Reverse Osmosis",
  "definition": "1. A membrane separation process designed to treat wastewater containing a variety of contaminants including organic compounds.\n\n2. (oz-MOE-sis) The application of pressure to a concentrated solution which causes the passage of a liquid from the concentrated solution to a weaker solution across a semipermeable membrane. The membrane allows the passage of the solvent (water) but not the dissolved solids (solutes). The liquid produced is a demineralized water.\n\n3. A treatment process used in water systems by adding pressure to force water through a semi-permeable membrane. Reverse osmosis removes most drinking water contaminants. Also used in wastewater treatment. Large-scale reverse osmosis plants are being developed.\n\n4. (For desalination) The process of removing salts from water using a membrane. With reverse osmosis, the product water passes through a fine membrane that the salts are unable to pass through, while the salt waste (brine) is removed and disposed. This process differs from electrodialysis, where the salts are extracted from the feedwater by using a membrane with an electrical current to separate the ions. The positive ions go through one membrane, while the negative ions flow through a different membrane, leaving the end product of freshwater.\n\n5. (For Water Quality) An advanced method of water or wastewater treatment that relies on a semi-permeable membrane to separate waters from pollutants. An external force is used to reverse the normal osmotic process resulting in the solvent moving from a solution of higher concentration to one of lower concentration.\n\n6. Reverse osmosis is a pressure-driven membrane separation process. Water is forced through a membrane with small pores by pressures ranging from 100 to 150 psi. Any molecules larger than the pore openings are excluded from the product stream along with a significant portion of the water. Treated water is collected on the other side.\n\n7. A membrane filtration method used to remove small ions (e.g., Na+) from wastewater that uses pressure as the driving separation force.",
  "abbreviation": "RO",
  "subject": "Environmental technologies",
  "references": [
    "Greening EPA Glossary",
    "Drinking Water Technical & Legal Terms",
    "Terms of Environment",
    "USGS Water Science Glossary of Terms",
    "EPA Radionuclides in Drinking Water at http://cfpub.epa.gov/safewater/radionuclides",
    "Effluent Limitations Guidelines (ELG) Glossary"
  ],
  "url": "https://mlchart.com/terminology/environment/reverse-osmosis/"
}