Standard methodology for evaluating membrane performance in osmotically driven membrane processes

Authors

Tzahi Y. Cath, Colorado School of Mines
Menachem Elimelech, Yale University
Jeffrey R. McCutcheon, University of Connecticut
Robert L. Mcginnis, Oasys Water
Andrea Achilli, Humboldt State University
Daniel Anastasio, University of Connecticut
Adam R. Brady, Colorado School of Mines
Amy E. Childress, University of Nevada
Isaac V. Farr, Hydration Technology Innovations
Nathan T. Hancock, Oasys Water
Jason Lampi, University of Nevada
Long D. Nghiem, University of WollongongFollow
Ming Xie, University of WollongongFollow
Ngai Yin Yip, Yale University

RIS ID

74772

Publication Details

Cath, T. Y., Elimelech, M., McCutcheon, J. R., Mcginnis, R. L., Achilli, A., Anastasio, D., Brady, A. R., Childress, A. E., Farr, I. V., Hancock, N. T., Lampi, J., Nghiem, L. D., Xie, M. & Yip, N. Yin. (2013). Standard methodology for evaluating membrane performance in osmotically driven membrane processes. Desalination, 312 (N/A), 31-38.

Abstract

Osmotically driven membrane processes (ODMPs) such as forward osmosis (FO) and pressure retarded osmosis (PRO) are extensively investigated for utilization in a broad range of applications. In ODMPs, the operating conditions and membrane properties play more critical roles in mass transport and process performance than in pressure-driven membrane processes. Search of the literature reveals that ODMP membranes, especially newly developed ones, are tested under different temperatures, draw solution compositions and concentrations, flow rates, and pressures. In order to compare different membranes, it is important to develop standard protocols for testing of membranes for ODMPs. In this article we present a standard methodology for testing of ODMP membranes based on experience gained and operating conditions used in FO and PRO studies in recent years. A round-robin testing of two commercial membranes in seven independent laboratories revealed that water flux and membrane permeability coefficients were similar when participants performed the experiments and calculations using the same protocols. The thin film composite polyamide membrane exhibited higher water and salt permeability than the asymmetric cellulose-based membrane, but results with the high permeability thin-film composite membrane were more scattered. While salt rejection results in RO mode were relatively similar, salt permeability coefficients for both membranes in FO mode were more varied. Results suggest that high permeability ODMP membranes should be tested at lower hydraulic pressure in RO mode and that RO testing be conducted with the same membrane sample used for testing in FO mode.