AWWA WQTC58796

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 organiccarbon and bromide ion from raw drinking water, thus lowering the ozonedemand of the water and its bromate formation potential. Several model and real rawdrinking waters containing different bromide ion concentrations and different totalorganic carbon (TOC) levels were treated with various doses of the MIEX resin using jartest 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 asemi-batch reactor and the formation of bromate and the removal of UV-absorbance wereevaluated as a function of ozone dosage and contact time. The results were compared tothose obtained by ozonating the water without MIEX-pretreatment.The results show that pretreatment of the waters with the MIEX resin substantiallyremoves UV-absorbing substances and removes bromide; the extent of bromide removalis related to the presence of competing anions such as bicarbonate and carbonate. Theozone demand of the waters was reduced substantially as a result of the removal oforganic material by pretreatment with the MIEX resin. Bromate formation was loweredonly in those cases where bromide removal was achieved by resin pretreatment. In thecases where bromide removal was minimal, i.e. in waters with high alkalinity (highbicarbonate and carbonate concentrations), the extent of bromate formation was the sameas in the controls which were not pre-treated with the MIEX resin, despite the loweredUV-absorbance and reduced ozone demand of the water. Includes 12 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/02/2003

Number of Pages:

15

File Size:

1 file , 350 KB