Water Treatment and Separation Science


Develop efficient systems for purification, disinfection, and desalinization water as well as removal of water from fermentation systems using novel mechanisms.

  • Inorganic membranes for disinfection and purification
  • Inorganic membranes and hydrates for dewatering of fermentation products in biofuel production
  • Inorganic membranes and hydrate formation for desalinization

Inorganic Membranes for Purification

  • The potential health threats associated with bacteria and viruses warrant development of robust filtering techniques capable of efficiently removing or concentrating biological agents from water and aerosols for water purification and disinfection.
  • ORNL Inorganic membrane surface filters appear well suited for bacterial and virus concentration and fluid filtration. The inorganic membranes exhibit high permeance at low backpressures, are robust, and can be rejuvenated upon combustion at 500°C for 8 hr, and appear to have cheaper material costs than traditional depth filters.
  • We have performed tests were performed using a stainless steel inorganic membrane filter exhibiting an average pore size of 4.2 um. The effectiveness of filtration was examined using 0.5 um diameter bacterial-sized fluorescent latex microspheres.
  • High permeance coupled with rejuvenation after combustion suggest that this filter may be suited for rapid long-term sample collection while smaller pore-size units may be better suited for tangential-flow fluid purification processes.
  • We are exploring applications of inorganic filters of various pore sizes and compositions for water purification and disinfection at various scales.

Inorganic Membranes for Biofuel Production

  • Currently, product inhibition and cost efficient product recovery are a significant problem in production of alcohols from biomass fermentation.
  • Our novel inorganic membranes could be used in a cost efficient separation process targeted at fuels and solvents resulting from fermentation of biomass.
  • By employing a membrane with the appropriate pore size and precise control of the temperature and pressure, the butanol and ethanol can be transported through the membrane by a combination of surface flow and capillary condensation.
  • The membranes are characterized by low back pressures and the ability to tailor the pore size to the specific application and thus they will require only simple and inexpensive pumps and supporting infrastructure.

Hydrates for Dewatering and Desalinization

  • The Environmental Sciences Division of ORNL operates the Seafloor Process Simulator (SPS) that is used to examine formation and behavior of hydrates.
  • Hydrates appear as a crystalline solid structure that consists of molecules of gas (such as methane, ethane, propane, and CO2), that are trapped by van der Waals forces inside a hexagonal cage-like structure of hydrogen-bonded water molecules.
  • Hydrates exclude aqueous species (e.g., sodium chloride and ethanol) from their crystalline structure, providing an opportunity for the separation of these species from water.
  • Thus, there is potential for use of hydrates in both desalinization (separation of salt and water) and biofuel production (separation of ethanol and water).

Advanced Ion Exchange Resins

  • New class of highly-selective resins designed for perchlorate (ClO4-) removal Innovative and cost-effective FeCl3- HCl regeneration technology.
  • Complete destruction of perchlorate in regenerant solution for repeated use -- no secondary wastes produced.
  • Patented, licensed, and winner of a 2004 R&D 100 Award.
  • Successful demonstrations of treatment of large volumes of perchlorate-contaminated water to below detection limits.
  • Technology applicable to a wide range of treatment situations, including tailoring functional groups and sorption sites for other target ions.
  • Both organic and inorganic mesoporous materials have been synthesized for this technology.

Related Links

For more information, contact:
Tommy Phelps (phelpstj@ornl.gov, 865-574-7290) - hydrates and membranes for water purificaiton
Brian Bishoff (bischoffbl@ornl.gov) - membranes
Tony Palumbo (palumboav@ornl.gov, 865-576-8002) - general
Baohua Gu (gub1@ornl.gov, 865-574-7286) - resins