Table 11.
Comparison of preservative solutions, DBNPA and CMIT/MIT (isothiazolone), with sodium metabisulfite for brackish water, polyamide membranes. Basis: 10,000 m3/day plant using 630 standard brackish water, polyamide membranes, 20 m3 preservative solution. Reproduced from WST:WS volume 11, issue number 3, pages 343–351, with permission from the copyright holders, IWA Publishing. [204].
| Biocide | Dosage, Active (ppm) | Dosage, Product (ppm) | Preservation Time (months) | Relative Product Cost | Relative Cost/month |
|---|---|---|---|---|---|
| Sodium metabisulfite | 3900 | 10,000 | 3 | 1 | 1 |
| DBNPA | 30 | 150 | 3 | 8.6 | 0.13 |
| CMIT/MIT | 10 | 71 | 6 | 10 | 0.036 |