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Demonstration of Pilot-Scale Pervaporation Systems for Volatile Organic Compound Removal from a Surfactant Enhanced Aquifer Remediation Fluid. II. Hollow Fiber Membrane Modules
Citation:
AbouNemeh, I., S. Majumdar, A. Saraf, K. K. Sirkar, L M. Vane*, F R. Alvarez*, AND L Hitchens*. Demonstration of Pilot-Scale Pervaporation Systems for Volatile Organic Compound Removal from a Surfactant Enhanced Aquifer Remediation Fluid. II. Hollow Fiber Membrane Modules. Bennett, G.F. (ed.), Environmental Progress & Sustainable Energy 20(1):64-73, (2001).
Description:
Pilot-scale demonstration of pervaporation-based removal of volatile organic compounds from a surfactant enhanced aquifer remediation (SEAR) fluid has been conducted at USEPA's Test & Evaluation Facility using hollow fiber membrane modules. The membranes consisted of microporous hydrophobic polypropylene fibers having a thin plasmapolymerized silicone layer on the outside surface. The SEAR fluid was allowed to flow through the fiber bores while vacuum was pulled on the shell side. The SEAR fluid was obtained from a pilot-scale demonstration of SEAR process at Hill Air Force Base, Layton, Utah. The extracted SEAR fluid from the site contained trichloroethylene (TCE) at 3,000 mg/L, 1, 1, 1-trichloroethane (TCA) at 450 mg/L and tetrachloroethylene (PCE) at 400 mg/L along with 2.5 wt% anionic surfactant, 1.5 wt% isopropyl alcohol, 1 wt% salt and a small amount of nonvolatile oil/grease. The hollow fiber modules were run for a period 0 8 - 10 hours everyday for a total of six weeks along with a continuous 40 hour run using the SEAR fluid. The modules were never washed with water or any other fluid. SEAR fluid flow rates of 0.25 - 1 gpm were employed; the temperature was varied between 35 - 45?C. Two membrane modules (each having an area of 3.06m2) used in series demonstrated stable removal of all of the VOCs without any substantial increase in the feed flow pressure drop. The water flux decreased continuously with time due to the accumulation of the nonvolatile oil/grease in the pores; the nonvolatile oil/grease also permeated through the silicone membrane. The performance of the hollow fiber modules was stable and satisfactory vis-a-vis VOC removal and pressure drop considerations.