You are here:
REMEDIATION FLUID RECYCLING: APPLICATION OF PERVAPORATION TECHNOLOGY TO MATERIAL RECOVERY AND REUSE
Citation:
Vane*, L M., F R. Alvarez*, L Hitchens*, J Springer* Jr., AND E Giroux. REMEDIATION FLUID RECYCLING: APPLICATION OF PERVAPORATION TECHNOLOGY TO MATERIAL RECOVERY AND REUSE. Presented at 2nd International Conference on Remediation on Chlorinated and Recalcitrant Compounds, Monterey, CA, 05/22-25/2000.
Description:
In an effort to aggressively remove NAPL source areas, agents such as surfactants and alcohols have been added to in situ flushing systems to enhance the solubility of the NAPL components. Such an approach has the potential to reduce the risk posed by a long term source of groundwater contamination. Unfortunately, these agents can be costly and will have their own environmental impact through the manufacture and use of the material. In order to reduce both the expense and impact of using these agents, decontamination and material recovery technologies must be employed which can deliver a reusable product - both from a regulatory and a technical standpoint - in a cost-effective manner. Pervaporation is a membrane technology which may prove useful for remediation fluid recycling.
In pervaporation, a liquid stream containing two or more components is placed in contact with one side of a non-porous polymeric membrane while a vacuum or gas purge is applied to the other side. The components in the liquid stream sorb into the membrane, permeate through the membrane, and evaporate into the vapor phase (hence the word pervaporate). The vapor, referred to as "the permeate", is then condensed. Due to different species in the feed mixture having different affinities for the membrane and different diffusion rates through the membrane, a component at low concentration in the feed can be highly enriched in the permeate. Concentration factors range from the single digits to over 1,000, depending on the compounds, the membrane, and process conditions. Process efficiency can be modified through membrane selection, module design, and control of process operating parameters.
Since 1994, researchers at the U.S. Environmental Protection Agency's (USEPA) National Risk Management Research Laboratory (NRMRL) have been investigating the use of pervaporation to remove VOCs from surfactant solutions, recover alcohols from surfactant-based flushing solutions, and remove water from