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3 pages Provider Notes:This page contains data on the project collected to date and documents meeting with the group. 06/25/03 Data from interview at NSCORT workshop. 09/26/05 Phone interview with Kim Jones by Jim Russell and Mike Lasinski. 05/03/06 Added 09/26/05 interview notes to file.This subsystem is part of the air/water treatment group. Following pretreatment by the Bio-Regenerative Environmental Treatment for Health (BREATHe)system, low pressure reverse osmosis (LPRO) or nanofiltration (NF) membranes will be employed to remove remaining contaminants including ammonium ions, surfactants, and trace organics. These contaminants will be reduced to meet existing EPA and NASA standards. The goal is to achieve high removal rates (99% for some contaminants) while maintaining high flux and low fouling of the membranes. Membrane treatment is the last treatment step before final disinfection of the recycled wastewater. Related Documents:WSR16a, WSR16c

18 slides Related Documents:WM1, WM2, WM3, WM8

Nanofiltration (NF) membranes typically carry a net electric charge, enabling electrostatic interactions to play a pivotal role in the rejection of species such as metals, nitrates, and other charged contaminants. In this study, two types of polymeric NF membranes, polyamide and cellulose acetate, were modified by ion implantation to increase the effective surface charge of the membranes. The modified membranes contain implanted ions in the membrane matrix, inducing a discrete, permanent charge in the active membrane layer. The presence of a permanent charge in the membrane matrix allows for increased electrostatic repulsive forces throughout the entire pH range. Streaming potential measurements were conducted as a function of pH for the modified and unmodified membranes to determine the effect of ion implantation on the zeta potential of the membranes. Rejection experiments were performed in order to quantify the effect of increased electrostatic repulsion on ion rejection, and flux measurements quantified the effect of the modification on permeability. Results indicate that electrostatic interactions near the membrane surface can affect rejection; however, the extent of the effect of increased membrane charge depends on physical-chemical characteristics of the membrane. Increased negative zeta potential of the modified membranes resulted in slightly higher rejection of salts with divalent co-ions from the membrane, with less increase observed with salts of monovalent co-ions. Modified membranes were less permeable than the unmodified membranes. Results of this research hold implications in membrane synthesis and modification studies as well as choice of membranes for water treatment applications. Description:7 pages

Progress of each ALS-NSCORT project given by each project lead. 9 pages.

This study involves modifying the surface of nanofiltration (NF) membranes by ion implantation for increased salt rejection. F? ions were implanted on the surface of commercially available nanofiltration membranes to increase the negativity of the membrane surfaces. The objective was to increase the Donnan exclusion effect and thus increasing the salt rejection by the modified membranes. A composite polyamide NF membrane (NF 90 Filmtec) and a cellulose acetate NF membrane (SP 28 Osmonics) were implanted with F? ions at two different intensities--1E10 and 5E10 atoms/cm2. Zeta potential measurements of the unmodified membranes and modified membranes show higher negativity with an increased intensity of ion implantation. Multicomponent salt permeation experiments were performed with the three types of membranes--the unmodified membrane and the two types of modified ones for both NF 90 and SP 28. The results show a decrease of solute flux for all the ions through the modified membranes when compared to that with the unmodified membrane. Initial experiments show no leaching of F? ions into the solution. Therefore, ion implantation on nanofiltration membrane surfaces is a novel technique to increase the salt rejection property of membranes. Description:8 pages

This study evaluates the use of microfiltration (MF), low pressure RO (LPRO) and nanofiltration (NF) membranes for use in a treatment train for recycled wastewater. Specifically, a MF membrane will act as pretreatment for RO/NF membranes. Contaminants of concern for the membrane system include biosolids and surfactant micelles for the MF membrane, and ammonium ions, urea, surfactant monomers, and salts for the RO/NF system. These contaminants will be reduced to meet existing EPA and NASA standards using these membrane systems. The goal is to achieve high removal rates (\mg95% for these contaminants) while maintaining high flux and low fouling of the membranes, as membrane treatment is the last treatment step before final disinfection of the recycled wastewater. This paper outlines the experimental plan for designing the integrated membrane system and explains the potential benefits of such a system. Description:5 pages