Evaluation of Alternative Filter Media for the Rotary Microfilter

Abstract

The Savannah River Site is currently developing and testing several processes to treat high level radioactive liquid waste. Each of these processes has a solid-liquid separation process that limits its throughput. Savannah River National Laboratory researchers identified and tested the rotary microfilter as a technology to increase solid-liquid separation throughput. The authors believe the rotary microfilter throughput can be improved by using a better filter membrane. Previous testing showed that asymmetric filters composed of a ceramic membrane on top of a stainless steel support produced higher filter flux than 100% stainless steel symmetric filters in crossflow filter tests. Savannah River National Laboratory and Oak Ridge National Laboratory are working together to develop asymmetric ceramic–stainless steel composite filters and asymmetric 100% stainless steel filters to improve the throughput of the rotary microfilter.

Keywords:

• composite membranes
• filter media
• filtration
• radioactive liquid waste
• rotary microfilter
• solid-liquid separation

ACKNOWLEDGEMENTS

The authors wish to thank the U.S. DOE Office of Environmental Management (EM-31) for funding this work. They would also like to thank Henry Bolton for performing the bench-scale filter tests and Dale Adcock and Larry Powell for membrane fabrication and characterization.

Notes

*Denotes pressure range from observation of first bubble to uniform bubbling along the entire sample using pure isopropanol.

*Based on SRS average salt solution.

^aStrontium carbonate measured in water. MST and sludge measured in salt solution.