The impacts of alum coagulation on the distribution of disinfection byproducts (DBPs),
trihalomethanes (THMs) and haloacetic acids (HAAs), were evaluated under controlled
chlorination conditions using four surface waters. Among the nine HAAs found in
waters, dihaloacetic acids (X<sub>2</sub>AAs) have been found to be the dominant species in all of
the raw and alum treated waters. Alum coagulation tends to remove more
monohaloacetic acids (XAAs) and trihaloacetic acids (X<sub>3</sub>AAs) precursors than that of
dihaloacetic acids (X<sub>2</sub>AAs). Alum coagulation treated water had a lower HAA<sub>9</sub>/TTHM
ratio compared with that of the raw water. The increase of THM bromine incorporation
factors (BIF<sub>α</sub>) value of alum treated water was statistically significant in comparison with
the raw water. On average, BIF<sub>α</sub> increased by 54% after the alum coagulation process in
these four different waters. This indicated that THM speciations shifted in favor of the
more brominated compounds. However, alum coagulation treatment process had less
effect on HAA bromine incorporation factors (BIF<sub>ß</sub>) than it did on BIF<sub>α</sub>. Bromine
Incorporation Factor (BIF) values decreased with time in the THM and HAA formation
processes, especially within the first 10 hours of the reaction time. This suggested that
brominated THMs or HAAs formed faster than the chlorinated species in the initial
period. Includes 22 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 15 |
| Published : | 11/15/2004 |
