Using reverse osmosis to obtain organic matter from surface and ground waters

Reverse osmosis (RO) is a rapid, powerful technique for concentrating dissolved organic matter (DOM) in surface and ground waters. The portable RO system used in our research group can process 150–2001 of water per hour with 90% recovery of organic carbon without exposing DOM to harsh chemical reagents. The system has been tested in blackwater streams, low-DOM streams, and in ground waters from very deep aquifers (> 1000 m). This paper discusses (1) percent recovery of organic carbon from a variety of surface and ground waters, (2) laboratory and modeling studies of the pH dependence of the recovery of low molecular weight organic acids from dilute solutions, and (3) operational factors that potentially affect the performance of the RO system in field experiments.