REFERENCE FACT SHEET
PROJECT DESCRIPTION
- Filtered water capacity 4,800 m³/d:
1,680 m³/d (phase 1); additional 3,120 m³/d (phase 2) - Brownfield EPC
- Modification of pre-treatment process steps, replacement of pressurized polymeric ultrafiltration
- Location: South Africa
- In operation since 01/2020
PROCESS CHAIN
- Blended feed water source from municipality and borehole
- Lime dosage for precipitation of calcium and magnesium for hardness reduction (lime softening)
- No settling of precipitants – direct transfer to filtration tanks
- Dead-end submerged ceramic flat sheet membrane filtration
- Activated carbon filters for dechlorination
- UV system
PROCESS FLOW DIAGRAM
PERFORMANCE DATA
The feed water is a blend of municipal and borehole water. Both water streams have different properties. The overall blending ratio is dependent on water availability and quality. Sudden and strong peak events have led to the damage of the previously installed polymeric membrane system.
CERAFILTEC’s softening filtration process enables operation even with high varying water properties. A small amount of lime is currently being dosed to reach a pH of about 9.6 to reduce calcium hardness only. During peak events, lime is overdosed to reach a pH of about 10.5 to additionally reduce magnesium hardness. In this case, the pH is subsequently adjusted to about 9.6 prior to the ceramic filtration to ensure stable long-term operation.
Regardless of the total hardness level and lime dosing requirements, all precipitants are directly transferred to the ceramic flat sheet membrane without settling step in between.
| PARAMETER | UNIT | FEED WATER | FILTERED WATER |
|---|---|---|---|
| T.H. | ppm | 80 (331*) | 26 |
| Sulphate | ppm | 98 (210*) | 82 |
| Silica | ppm | 41 (80*) | 36 |
| TDS | ppm | 365 (421*) | 290 |
| TSS | ppm | 3 (301**) | < 1 (nil) |
| Turbidity | NTU | 0.67 (49**) | 0.17 |
| pH | 7.6 (9.6**) | 9.6 |
| PARAMETER | UNIT | VALUE |
|---|---|---|
| No. of trains | 9 | |
| Max. flow per train | m³/hr | 36.2 |
| Max. flux rate | LMH | 251 |
| Filtration time | hrs | 4 x 3.93 |
| Backwash time | sec | 4 x 70 |
| Recovery rate | % | 96.1 |
| Power consumption | kWhr/m³ | 0.02 |
* feed water max values during peak events; ** after lime dosage (inside filtration tank)
| T.H. | Feed water 80 (331*) ppmFiltered water 26 ppm |
| Sulphate | Feed water 98 (210*) ppmFiltered water 82 ppm |
| Silica | Feed water 41 (80*) ppmFiltered water 36 ppm |
| TDS | Feed water 365 (421*) ppmFiltered water 290 ppm |
| TSS | Feed water 3 (301**) ppmFiltered water < 1 (nil) ppm |
| Turbidity | Feed water 0.67 (49**) ppmFiltered water 0.17 ppm |
| pH | Feed water 7.6 (9.6**)Filtered water 9.6 |
* feed water max values during peak events
** after lime dosage (inside filtration tank)
| No. of trains | 9 |
| Max. flow per train | 36.2 m³/hr |
| Max. flux rate | 251 LMH |
| Filtration time | 4 x 3.93 hrs |
| Backwash time | 4 x 70 sec |
| Recovery rate | 96.1 % |
| Power consumption | 0.02 kWhr/m³ |
PLANT PICTURES
