AWWA ACE58229

Researchers have noted that Mg(OH)2 solidsreduce natural organic matter (NOM) concentrations significantly more efficiently than CaCO3 solids. Todate, enhanced softening research indicatesmagnesium plays an important role in NOM removal even at pH values below thatrequired for precipitation of Mg(OH)2, possibly due to the formation of mixed Mg-CaCO3 precipitates. Unfortunately, little is known about these minor precipitatesformed in softening, and hence the positive impact cannot be systematically takenadvantage of in operating treatment plants. This research attempts to close the gapin softening research by: determining the chemical composition and structure ofsolids formed under various softening conditions (e.g., Ca:Mg ratio of the raw waterand pH of softening); and, investigating the capability of removing natural organicmatter depending on the chemical and surface characteristics of the solids formed(e.g., degree of incorporation of minor constituents in solids, surface charge, shape). Includes 10 references, table, figures.

Product Details

Edition:

Vol. - No.

Published:

06/15/2003

Number of Pages:

10

File Size:

1 file , 1000 KB