Amsterdam water supply considers the use of hyperfiltration for direct treatment of coagulated and prefiltered water from the River Rhine. At the moment research is being carried out on pilot plant scale into hyperfiltration and the required pretreatment. With respect to scaling, process conditions have been developed to avoid precipitation of barium sulfate in the membrane modules. By using 2 mg/l Flocon 100 as anti-scalant, sulfuric acid dosing to reach a LSI (Langelier Saturation Index) in the concentrate of 2 and a recovery rate of 90%, scaling can be avoided. Also, without an anti-scalant, barium sulfate precipitation can be avoided, provided that the recovery is lowered to 80% and hydrochloric acid is dosed up to a LSI of 0 in the concentrate. With respect to fouling, two pretreatment schemes for the coagulated and prefiltered River Rhine water have been compared: ozonation--biological activated carbon filtration--slow sand filtration; and slow sand filtration. The extended pretreatment scheme results in a better feedwater quality for the hyperfiltration units, and less fouling. An additional benefit of the use of activated carbon filtration in the pretreatment scheme is the removal of organic micropollutants (especially AOX) from the feedwater of the hyperfiltration units. This results in a lower AOX-content in the concentrate, and enables the discharge of the concentrate into the North Sea.
| File Size : | 1
file |
| ISBN(s) : | 0898678153 |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 18 |
| Published : | 01/01/1995 |
