Due to the well-known limitations of the conventional processes for iron and manganese removal
(chemical dosage, pollutants, etc.), operators of drinking water plants are interested in alternative processes
such as the catalytic process. In this context, this project examined the catalytic technique and then
developed operational guidelines. Batch characterization of commercial materials performed in this study
indicated that MnO<sub>2</sub> natural ores perform better than other materials in terms of manganese
removal. Among the same type of material, the retention capacity varies up to a factor of three, which
indicates the need to test new material before implementation at full-scale. Pilot scale experiments demonstrated that the retention capacity was not proportional to the inlet concentration and that
manganese breakthrough appears before reaching maximum retention capacity. Chlorinated backwashes
as well as a chlorine soaking do not allow for a complete regeneration of a fully saturated material. A complete regeneration of the material was obtained with permanganate soaking but breakthrough occured rapidly. A weekly chlorinated backwash increased the BVs before manganese breakthrough but not in a large extent. Only a continuous pre-oxidation associated with the catalytic media was found effective to ensure final water quality below 10 µg/L for water resources containing above 300 µg/L of manganese. Observation of the surface of the catalytic media at different stages of saturation by scanning electron microscopy explains the differences of manganese retention efficiency related to the feasibility of regenerating the surface of
the media. The main limitation of this technique is pH-dependence, but the overall study demonstrates
the benefit and ease of using catalytic media for manganese removal. Includes 10 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 950 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 13 |
| Published : | 11/01/2009 |
