A systematic investigation about both the formation and control of halonitromethanes (HNMs) were conducted in
this study. The disinfectants applied included ozone, chlorine, monochloramine, and ozone
followed by chlorine or monochloramine. Raw (i.e., the influents to the treatment plants) and
treated waters (i.e., the water after conventional treatment processes but before any addition of
disinfectants) from five drinking water treatment plants in South Carolina (Charleston,
Greenville, Myrtle Beach, SJWD, and Spartanburg) were collected and investigated at different
times in a year. The results showed that HNMs molar concentrations (22-67 nM) and molar
yields (10-40 nM/DOC) were the highest by the treatment of ozonation-chlorination, followed by
chlorination, ozonation-chloramination, and chloramination treatment in both raw and treated
waters. Higher HNMs yields were observed in the treated water than the raw water at each
treatment plant, indicating that the conventional treatment processes did not remove major
HNMs precursors. The results suggest that the most hydrophilic NOM fractions (HPI) that are
not removed by conventional treatment processes contain the major HNM precursors. It was also
found that HNMs yields increased with decreasing DOC/DON ratios (i.e., increasing nitrogen
content per organic carbon in water), and the nitrogenous organic compounds, such as
aminosugars or amino acids, are the most likely precursors of HNMs. It appears that DOC/DON
ratio can be a simple method for utilities to asses the presence of HNM precursors in natural and
treated waters. Includes 13 references, table, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.5 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 64 |
| Published : | 11/01/2008 |
