Appendix 3. Methods for measuring transparent exopolymer particles and their precursors in seawater.

Abstract

Transparent exopolymer particles (TEP) and their precursors produced by phyto-/bacterioplankton in fresh and marine aquatic environments are increasingly considered as a major cause of organic/particulate fouling in MF/UF membranes and organic/particulate and biological fouling in SWRO membranes. The following sections comprise detailed descriptions of two methods for measuring transparent exopolymer particles in seawater, namely TEP0.4μm and TEP10kDa. The TEP0.4μm method measures transparent exopolymer particles retained by membrane filters having pores of 0.4 μm and conventionally known as TEP (Passow and Alldredge, 1995). The TEP10kDa method covers transparent exopolymer particles retained by membrane filters with molecular weight cut-off of 10 kDa. Consequently, this method covers both TEP and most (if not all) of their colloidal precursors. TEP0.4μm is a more rapid method than TEP10kDa and is recommended for routine TEP monitoring in untreated seawater. The TEP10kDa method is more time consuming, however, it gives much more information because it covers both TEP and their colloidal precursors.