Coagulation of natural organic material: effects on speciation of halogenated disinfection by-products

A recent paper by Liang and Singer showed that haloacetic acid (HAA) precursors were removed by coagulation to a greater degree than trihalomethane (THM) precursors. Furthermore, they showed that coagulation generally removed more trihaloacetic acid precursors than THM precursors but removed dihaloacetic acid precursors and THM precursors to a similar degree. The objectives of this current study were to compare the findings by Liang and Singer to those of three other investigations conducted in the senior author's laboratory to demonstrate the extent to which coagulation removes THM and HAA precursors, and to contrast the removal of dihaloacetic acid and trihaloacetic precursors by coagulation. These other studies were conducted on seventeen other waters from across the US.