The Metropolitan Water District of Southern California initiated a study to evaluate
manganese (Mn) desorption from filter media during biological filtration start up. Mn
contamination of the filter media was a byproduct of multiple years of pre-chlorination
while using Mn-containing ferric chloride (FeCl<sub>3</sub>) for coagulation. During pilot- and fullscale
testing, FeCl<sub>3</sub> coagulation (without chlorine) released soluble Mn at nearly four
times the level compared to alum (105 µg/L for FeCl<sub>3</sub> and 27 µg/L for alum). Pilot-scale
experiments led to the conclusion that Mn was present in the filter column in three
valance states [Mn(II), Mn(III), and Mn(IV)]. Mn in the filter effluent was hypothesized
to be first physically displaced as Mn(III) from anthracite media by ferric iron,
aluminum, and hydrogen, and then catalytically oxidized to Mn(IV) by silica sand. Includes 34 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 610 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 19 |
| Published : | 11/01/2005 |
