EUROWATER offers an SDI measuring equipment fitted with high quality components for an accurate SDI analysis.
For further information and request of data sheet, please contact your local sales and service office.
The sheet shows common measurements for quick reference. For reliable results, at least two measurements must have similar SDI values (+/- 0,5).
SDI1 = 3, SDI2 = 3,5: The measurement is acceptable
SDI1 = 3, SDI2 = 3,7: The measurement is NOT acceptable
SDI = 0-3: Standard conditions apply.
SDI = 3-5: Special operating data for recovery and permeate flow apply as stated in plant instructions.
SDI = 5-6: The water is not suitable for feeding an NF or RO plant unless the colloidal content is reduced by supplementary pre-treatment, i.e. flocculation.
The filters show how colloids and suspended solids can foul the filter of the measuring equipment.
Water with an SDI >5 (right) is unsuitable for RO or NF treatment.
Water with SDI above 5 is unsuitable for RO or NF treatment. But proper pre-treatment or alternative technologies can provide you with demineralized water.
Pre-treatment is necessary to protect and extend the lifetime of the membranes. A bag filter has a robust design and comply with demands on flow rates and space.
A pressure filter can also function as a pre-filter to RO or NF. The content of metal and salts in the inlet water determine the selected filter material.
Prevent hardness minerals from clogging the membranes by water softening. Softening can also be achieved through dosing of antiscalants that keep hardness minerals dissolved.
A filter with a density of 1 µ protects the RO membranes against suspended solids. Free chlorine in the water can be removed in an activated carbon filter.
A demineralizer requires no special pre-treatment of the inlet water to achieve demineralized water quality. The plant is very robust and use a two-column ion exchange system.
Our international sales and service organization is ready to guide you to an optimum solution based on your SDI value. Please contact us for further information.