AWWA JAW20885

Ever since the city of Newport News, Virginia, eliminated prechlorination at its water treatment facilities in 1982 in order to control trihalomethanes, it has been plagued by deterioration of alum sludges in manually cleaned sedimentation basins and by occasional declines in settled water quality. Laboratory and field studies showed that anaerobic conditions develop rapidly in manually cleaned sedimentation basins (but not in those that are mechanically cleaned), allowing manganese to be released from the sludge into the overlying water. The use of chlorine dioxide as a preoxidant was found to suppress this release of manganese, produce sludges with improved dewatering characteristics, and lengthen filter runs. Includes 1 reference, figures.

Product Details

Edition:

Vol. 79 - No. 6

Published:

06/01/1987

Number of Pages:

9

File Size:

1 file , 2.2 MB