Accepta 2091 is a high performance reverse osmosis (RO) antiscalant and dispersant, scientifically formulated for the treatment and protection of reverse osmosis membranes under high silica feed water conditions.
A proprietary blend, Accepta 2091 has been specifically designed for ro membrane systems with high silica feed-waters.
Accepta 2091 can be used in reverse osmosis applications where the reject brine silica levels are as high as 230 ppm at 30oC and pH 7.5.
Scaling and deposits build up on the reverse osmosis membranes leading to poor permeate quality, low permeate production and increased water and energy costs.
Accepta 2091 is a proven high performance scale inhibitor against calcium carbonate and calcium sulfate scalants and combats silica fouling by a combination of anti-precipitation, anti-agglomeration and dispersancy processes.
Accepta 2091 is compatible with a wide range of materials and unlike other antiscalants, is not deactivated in the presence of iron.
- Highly efficient antiscalant and dispersant for reverse osmosis membrane systems
- Designed for high silica feedwaters
- Very effective antiscalant
- Prevents low production and poor permeate quality
- Prevents downtime and increased costs
- Combats silica fouling
- Is not deactivated in the presence of iron
|Specific gravity:||1.22 (15.6 °C)|
|Flash point:||> 93.3 oC|
|pH:||9.2 – 10.2|
|Solubility in water:||Complete|
*Full details of the product properties are available in the Accepta MSDS.
Application & Dosage Information
|All membrane elements based on Polyamide
chemistries including Thin Film Composite (TFC)
membranes when used as directed
|304 Stainless Steel||EPDM|
Product Feeding And Program Compatibility
It is preferred to feed Accepta 2091 neat via a closed feed system to prevent contamination from foreign material (a closed feed system being defined as a system in which fluid is moved from a closed storage vessel into a treated media without exposure to the atmosphere, except through normal venting or pressure relief devices.)
Accepta 2091 MUST be fed continuously to minimize precipitation of scale and fouling of RO membranes.
It is recommended to operate the dosing pump with the highest possible stroke frequency and to apply the proper dosage by adjusting the pump stroke to insure membrane protection.
Accepta 2091 can be diluted using RO permeate (only) following these guidelines:
- Use RO permeate for dilution.
- Prepare a fresh antiscalant solution every 2-3 days.
- Inspect the antiscalant day-tank before adding the new solution. If needed, the antiscalant tank should be cleaned prior to filling.
- Dilution rates up to a factor 10 can be applied.
- NaOH can be added to the dilution to increase the pH to 10-11. This is especially recommended for warm environments to prevent bio-growth.
Accepta 2091 recommended dosage is 1 ppm in the feedwater for every 6 to 10 ppm of total silica in the feedwater, depending on the operating pH and temperature.
With high silica brines, 180 to 230 ppm (in the concentrate), it is essential the correct dosage of Accepta 2091 be present in the feedwater at all times. Silica fouled membranes are extremely difficult to clean.
Silica fouling is difficult to predict as both dissolved and colloidal silica may be present and their reaction chemistry is complex.
The prevention of substrate material such as insoluble calcium and iron salts is an important aspect in preventing silica fouling.
NOTE: It is essential that effective auto-permeate flushing devices be used with high silica waters. These devices allow permeate to be used to rinse out feed water which contains upersaturated salts and treatment chemicals before shutting the system down.
Manual Calculation of Feed Water Dosage for Accepta 2091
SiO2 mg/L in the feed water = SiO2-fw
pH feed water = pHfw
Feedwater temperature = TFW
Percent Recovery of the system = R
(note use percent in the decimal form for calculations e.g., 75% = 0.75)
- Calculate the Concentration Factor (CF): CF = 1/(1- R)
- Calculate the theoretical concentration of Silica in the brine SiO2-brine = SiO2-fw * CF
- Determine the brine pH (pHb) based on pHfw and system recovery from Chart #1
- Determine the SiFactor from Table #1
- Determine the Saturation Index (SI) for the system SI = SiO2brine/SiFactor
NOTE: Accepta 2091 should only be used for Saturation Index between 1.54 and 2.07.
When the Saturation Index is less than 1.54 use alternative Accepta product.
If Saturation Index is greater than 2.07, then contact Accepta.
6. Calculate the concentration of ACCEPTA 2091 required in the brine ACCEPTA 2091 brine
ACCEPTA 2091 brine = (2.25) + (17.16) * (SI – 0.8)
7. Calculate the feedwater dosage of ACCEPTA 2091 fw ACCEPTA 2091 fw = ACCEPTA 2091brine / CF
It is advisable to carry out a ‘Control Of Substances Hazardous to Health’ (COSHH) assessment before use.
Contact Accepta technical support for additional technical advice.