This study was undertaken to solve the problem of removal of sulfate and silica from solutions of natural organic matter (NOM) that had been pre-concentrated by reverse osmosis. The goal is the development of a method by which NOM can be concentrated and This study was undertaken to solve the problem of removal of sulfate and silica from solutions of natural organic matter (NOM) that had been pre-concentrated by reverse osmosis. The goal is the development of a method by which NOM can be concentrated and