DOSAGE AND FEEDING

ORG - 191 t (Membrane Antiscalant) be fed continuously to minimize precipitation of scale and fouling of RO and nanofiltration membranes. The feedpoint location should be as close to the RO membrane as practical but one that ensures good mixing with the feedwater prior to entering the RO system. Typically, this is before the cartridge filters.

All new installations of ORG - 191 t (Membrane Antiscalant) should begin with a 2 week monitoring phase during which current operating conditions should be maintained (i.e. setting pumps manually based on stroke length and frequency). After this evaluation period, TRASAR-based control of the system should be instituted using the recommended pump.

It is preferred to feed ORG - 191 t (Membrane Antiscalant) 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).

ORG - 191 t (Membrane Antiscalant) can be diluted using RO permeate (only) following these guidelines:

1. Use RO permeate for dilution.
1. Prepare a fresh antiscalant solution every 3-5 days.
1. Inspect the antiscalant day tank before adding the new solution. If needed, the antiscalant tank should be cleaned prior to filling.
1. Dilution rates up to a factor 10 are typically applied. Dilution factors higher than 10 will require more attention with respect to the condition of the antiscalant tank (cleaning) and preparation of a new solution (every 1-3 days).
1. 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.

ORG - 191 t (Membrane Antiscalant) dosage is dependent on feedwater chemistry, membrane type, and system operating parameters (e.g., recovery, temperature and pressure). These parameters determine the potential foulant that is likely to foul the membrane elements.

To determine the optimum product dosage for your system, it is recommended that you use the RO Optimizer chemical projection computer program. This program will select the appropriate scale inhibitor treatment program and calculate the recommended dosage based on the RO design and operation as well as feedwater or brine chemistry. This program will do all calculations for you easily and automatically.

CONSEQUENCES OF OVERFEED
Overfeed of ORG - 191 t (Membrane Antiscalant) will result in a higher chemical cost.

CONSEQUENCES OF UNDERFEED
Underfeed of ORG - 191 t (Membrane Antiscalant) will result in poor scale inhibition. This will lead to fouled RO membranes, and reduced system performance and/or premature membrane replacement. In RO units, scaling is typically seen in the tail-end elements that have the highest reject concentration (4:1 for a 75% recovery system).