A successful arsenic removal technology must be
capable of removing both arsenate and arsenite.
Research has shown that low-pressure nanofiltration
(NF) membranes remove most of the arsenate but only
some of the arsenite. To exploit membrane filtration's
ability to remove arsenate, several researchers have
suggested that a pretreatment step oxidizing arsenite to
arsenate would improve the performance of NF membranes.
The current study investigated this hypothesis by
assessing the effect of the oxidation step on the arsenic
removal performance of two NF membranes and a low-energy
reverse osmosis membrane.
Because of its inert nature, long life, simple operation,
and compatibility with oxidant-sensitive membranes,
manganese dioxide was chosen as the companion
oxidant for membrane filtration. Results
indicated that preoxidation with manganese dioxide
significantly enhanced arsenic removal. For treatment
facilities using membrane filtration to treat
hard or brackish water, manganese dioxide may
provide a low-maintenance, cost-effective pretreatment
alternative if additional arsenic removal is
required to meet the regulatory target of 10 µg/L
arsenic. Includes 38 references, tables, figures.
| Edition : | Vol. 100 - No. 12 |
| Number of Pages : | 10 |
| Published : | 12/01/2008 |
