Lyophilization and Reconstitution of Reverse-Osmosis Concentrated Natural Organic Matter from a Drinking Water Source

Abstract

Drinking water treatment research can be complicated by difficulties in shipping large water quantities and changing natural organic matter (NOM) characteristics over time. To overcome these issues, it is advantageous to have a reliable method for concentrating NOM with minimal loss and maximum shelf-life. NOM concentration and preservation by lyophilization (freeze-drying) has been practiced for many years; however, little information for lyophilizing and reconstituting NOM exists in the literature. The purpose of this research was to both evaluate and improve the lyophilization process of a concentrated NOM solution and to determine the appropriate conditions (pH, mixing time, and concentration factor) under which to reconstitute lyophilized NOM for maximum total organic carbon (TOC) and ultraviolet absorbance at 254-nm