Arsenic exists in two oxidation states in water,
arsenite [As(III)] and arsenate [As(V)]. As(III) is relatively
mobile in water and difficult to remove by
arsenic-removal treatment processes. Source waters
that contain As(III) must add a strong oxidant such as
free chlorine or permanganate to oxidize the arsenic.
This article highlights an Ohio treatment plant where
natural bacteria in the source water concentrate in
filters and oxidize As(III), eliminating the need for a
strong oxidant ahead of filtration. Microbial filtration
also provides secondary benefits such as reduced chemical-
handling issues, maintenance of nitrification capacity
in the filters, elimination of nitrification potential in
the distribution system, and reduced chlorine demand
in the finished water.
Microbial treatment of drinking water is not widely
accepted in the United States. Results of this research
demonstrated that As(III) oxidation and its subsequent
removal can occur microbially, offering an alternative,
nonchemical approach to As(III) oxidation and a safe
and relatively simple means of meeting the arsenic
drinking water standard. Includes 43 references, tables, figures.
| Edition : | Vol. 99 - No. 12 |
| File Size : | 1
file
, 390 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 15 |
| Published : | 12/01/2007 |
