The presence of iron and manganese in drinking water distribution systems is a concern as it
reduces the aesthetic quality of the water. When dissolved iron and manganese are oxidized, they
form insoluble compounds that precipitate and cause yellowish to reddish-brown to black
staining, depending on the relative abundance of each metal. In order to improve the aesthetic
quality of drinking water, the US Environmental Protection Agency National Secondary Drinking Water Regulations suggest
maximum concentrations of 0.30 mg/L and 0.05 mg/L for iron and manganese, respectively. The
ZeeWeed(R) Ultrafiltration Membrane system can remove particles that are greater than 0.1
microns in size, including iron and manganese precipitates. For the removal of dissolved iron and
manganese, an oxidation step is added prior to the membrane, which converts the dissolved
species into their insoluble forms. Oxidation may be achieved by aeration or by the addition of
oxidizing chemicals such as chlorine, chlorine dioxide or potassium permanganate.
For water sources requiring both removal of dissolved organics and dissolved iron and
manganese, ZENON has developed a unique process in which the ZeeWeed(R) Ultrafiltration
Membrane system can be coupled with a single step coagulation-oxidization process. This paper
discusses critical process issues required to prevent membrane fouling and to achieve the
treated water quality objectives with respect to organics and iron and manganese removal while
utilizing the simultaneous step coagulation-oxidation process. This paper also presents the
results from numerous pilot studies conducted to demonstrate the capabilities of ZeeWeed(R) 500
immersed membrane system to combine both of these pretreatment steps. A detailed discussion
evaluates the effects of different operating parameters on TOC, color, iron and
manganese removal from surface waters and groundwaters. Includes 4 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 780 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 19 |
| Published : | 03/05/2003 |
