The objective of this research was to examine the impact of a magnetic ion exchange
(MIEX) resin on subsequent ozonation of drinking water. The resin removes organic
carbon and bromide ion from raw drinking water, thus lowering the ozone
demand of the water and its bromate formation potential. Several model and real raw
drinking waters containing different bromide ion concentrations and different total
organic carbon (TOC) levels were treated with various doses of the MIEX resin using jar
test procedures to select the optimal resin dosage based upon the removal of ultraviolet
(UV)-absorbing substances, TOC, and bromide. The waters were then ozonated in a
semi-batch reactor and the formation of bromate and the removal of UV-absorbance were
evaluated as a function of ozone dosage and contact time. The results were compared to
those obtained by ozonating the water without MIEX-pretreatment.
The results show that pretreatment of the waters with the MIEX resin substantially
removes UV-absorbing substances and removes bromide; the extent of bromide removal
is related to the presence of competing anions such as bicarbonate and carbonate. The
ozone demand of the waters was reduced substantially as a result of the removal of
organic material by pretreatment with the MIEX resin. Bromate formation was lowered
only in those cases where bromide removal was achieved by resin pretreatment. In the
cases where bromide removal was minimal, i.e. in waters with high alkalinity (high
bicarbonate and carbonate concentrations), the extent of bromate formation was the same
as in the controls which were not pre-treated with the MIEX resin, despite the lowered
UV-absorbance and reduced ozone demand of the water. Includes 12 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 350 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 15 |
| Published : | 11/02/2003 |
