This powerpoint presentation begins by providing a brief overview of tastes and odors (T&O) in developed countries. A flavor profile analysis of Boussy St Antoine
raw and chlorinated water (Dec 1985) is presented, along with THM's identified by SDE-GC-MS (Boussy
St Antoine, Dec 1985). Topics presented include: Weber-Fechner curve for Iodoform and
Bromoform (medicinal descriptor); literature review of odor thresholds for
various THM (FPA method: 45ºC); Vernouillet case study of
chlorination of groundwater containing
ammonia; role of ammonia in iodinated THM
formation (Gittelman and Yohe, 1989); Cassan Treatment Plant (December
1996); taste intensity as a function of chlorine dose; Cassan case study conclusion; compared formation of iodoforms (µg/L) with
chlorine and chlorine dioxide (La Falaise groundwater); formation mechanism of
iodinated THM
Bichsel et al., 1999
HOI/OII-I; iodides in the environment; analytical methods for iodides and iodo
THMs and I-HAAs; and, identification of iodoacetic acid in methylated acidic
extract (Bordeaux area, July 1994) during
medicinal odor episode. Conclusions indicate that: medicinal taste and odor episodes caused by
iodinated DBP's have been observed at dozens of sites
scattered throughout France;
all of them were observed in groundwaters
containing 20-100 µg/L of iodides and disinfected with
chlorine only (chloramines are not allowed in France);
iodoacids not investigated but detected on one
occasion; most iodoform problems
were solved by switching
from chlorine to chlorine
dioxide;
chloramination where
ammonia is added before
chlorine or at the same
time encourages
formation of iodinated
species;
larger contact times (> 5
minutes) with chlorine
before ammoniation
reduces formation of
iodinated species; and,
removing the iodide precursors
with a strong oxidant prior to
disinfection may be the best
option. Includes tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.3 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 23 |
| Published : | 11/01/2009 |
