A review of different drinking water treatments for natural organic matter removal

In the past decades, natural organic matter (NOM), which is a complex heterogeneous mixture of organic materials that are commonly present in all surface, ground and soil waters, has had an adverse effect on drinking water treatment. The existence of NOM results in many problems in drinking water treatment processes, and the properties and amount of NOM can significantly affect the efficiency of these processes. NOM not only influences the water quality with respect to taste, color and odor problems, but it also reacts with disinfectants, increasing the amount of disinfection by-products. NOM can be removed from drinking water via several treatment processes, but different drinking water treatment processes have diverse influences on NOM removal and the safety of the drinking water. Several treatment options, including coagulation, adsorption, oxidation, membrane and biological treatment, have been widely used in drinking water purification processes. Therefore, it is of great importance to be able to study the influence of different treatment processes on NOM in raw waters. The present review focuses on the methods, including coagulation, adsorption, oxidation, membrane, biological treatment processes and the combination of different treatment processes, which are used for removing NOM from drinking water.