Selected processes for removing NOM: an overview

GAC adsorption and membrane processes offer alternatives to enhanced coagulation for removing NOM. As a result of the anticipated Disinfectants/Disinfection By‐product Rule, there has been increasing emphasis by the water industry on the removal of natural organic matter (NOM) from raw‐water supplies. Three important NOM removal options are coagulation, granular activated carbon (GAC) absorption, and membrane filtration. Of these three processes, coagulation is the most widely used in the water industry. But when coagulation cannot remove adequate concentrations of NOM so that disinfection by‐products can be controlled, other treatment technologies such as GAC and nanofiltration may need to be used Various aspects of each of these technologies are discussed.