Experiments were performed in the presence and absence of background ammonia to
study the significance of the direct reaction(s) of monochloramine (NH<sub>2</sub>Cl) with dissolved
organic matter (DOM) in the haloacetic acid (HAA) formation during chloramination. Direct
reactions were found to play a major role in the HAA formation compared to the reactions of
NH<sub>2</sub>Cl decomposition products (i.e., hypochlorous acid and dichloramine) with DOM.
Dihalogenated HAAs (DXAA) constituted the major HAA<sub>9</sub> species formed during
chloramination. The extent of DXAA formation decreased with increasing pH. Experiments
conducted with sodium sulfite (Na2SO3) and ammonium chloride (NH4Cl) showed that selection
of quenching agent is important to obtain reliable results from chloramination kinetic
experiments. When preformed chloramines are employed, the use of NH<sub>4</sub>Cl, the quenching
agent recommended by USEPA Method 552.3 for HAA samples, may result in false high HAA
concentrations at early reaction periods. The type of quenching agent used in different studies
appears to be the cause of different kinetic patterns reported for chloramination kinetics in the
literature. Includes 16 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.2 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 16 |
| Published : | 06/17/2005 |
