Manganese removal during bench-scale biofiltration.
As biological manganese (Mn) removal becomes a more popular water treatment technology, there is still a large gap in understanding the key mechanisms and range of operational characteristics. This research aimed to expand on previous bench-scale experiments by directly comparing small filtration columns inoculated with indigenous biofilms from a Mn filtration plant and filtration columns inoculated with a liquid suspension of Leptothrix discophora SP-6. Batch tests found that in the absence of manganese oxidizing bacteria Mn was not removed by air alone, whereas a mixed population and Leptothrix strain achieved greater than 90% removal of Mn. The bench-scale biofiltration experiments found that biological filters can be inoculated with a pure culture of L. discophora SP-6 and achieve a similar removal of indigenous biofilm. While Mn oxidizing bacteria (MOB) seem to be necessary for the auto-catalytic nature of these biological filters, Mn removal is achieved with a combination of adsorption to Mn oxides and biological oxidation. Additionally, it was demonstrated that biological Mn removal is possible over a broader "field of activity" (e.g., Mn removal occurred at a pH level as low as 6.5) than has previously been reported. The ability of this treatment technology to work over a broader range of influent conditions allows for more communities to consider biological treatment as an option to remove Mn from their drinking water.
Burger
Mark S
MS
Department of Civil and Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, Nova Scotia B3J 1Z1, Canada.
Mercer
Stephen S
SS
Shupe
Gordon D
GD
Gagnon
Graham A
GA
D000327:Adsorption; D001483:Base Sequence; D017931:DNA Primers; D052918:Environmental Restoration and Remediation / Q000379:methods; D005374:Filtration / Q000379:methods*; D042743:Leptothrix / Q000378:metabolism*; D008345:Manganese / Q000302:isolation & purification*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; D008345:Manganese