AWWA WQTC69413

In order to comply with the United States Environmental Protection Agency's (USEPA's) arsenic standard and the manganese and iron secondary maximum contaminantlevels (MCLs) in water (10µg/L, 50µg/L, and 300µg/L, respectively), many Midwesternwater utilities must add a strong oxidant before filtration to oxidize the reduced forms ofarsenic, manganese and iron. Free chlorine and permanganate are the two most commonchemical oxidants used to address arsenic, manganese, and iron issues. In the Midwestern UnitedStates, engineering practices have traditionally favored the use of permanganate as theoxidant of choice, followed by green sand filtration to remove manganese from sourcewaters. Most water treatment plant personnel, however, find permanganate undesirable touse for a number of reasons, including: it stains everything it contacts; overdosing causes"pink" water; under-dosing can cause manganese spikes; and, handling issues. There is areal need to compare the effectiveness of chlorine and permanganate in manganese (andarsenic) removal systems and, more importantly, to provide better guidance as to wheneach oxidant is most appropriate to address an iron, manganese, and/or arsenic problem.Observations from full-scale treatment plants are used to illustrate the appropriateapplications of chemical oxidants. Includes 2 references, table, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2008

Number of Pages:

5

File Size:

1 file , 750 KB