Nalco PermaTreat PC-191: RO Membrane Antiscalant Reverse osmosis is a water purification

technique developed in 1950’s by US

government to remove dissolved solids in

saline and brackish water. The principle

involves application of waterline pressure

over untreated water against a

semipermeable membrane. The separated

H2O molecules pass through the membrane

into a reservoir while contaminants remain

on the other side. Over the years, RO has

been extensively used for treating

industrial feed water. While the primary

method for demineralization is Ion

exchange method, RO systems are adopted when large volumes of water need to be treated economically.

The life, efficiency & productivity of an RO Membrane water treatment system is greatly reduced due to a phenomenon

called RO Membrane Scaling. During RO system operation, as the water moves through the membrane, the

concentration of dissolved and suspended solids keep on increasing at the boundary layer. When the concentration

exceeds saturation value, there occurs a tendency of deposition and crystallization on the membrane surface. Smaller

depositions act as nuclei for more salt accumulation thus decreasing effectiveness of membranes and invoking frequent

cleaning of the system. Scalants mostly include low soluble salts of calcium, barium, strontium as carbonates and

sulfates and fine reactive silica crystals. Their low solubility makes them difficult to remove during cleanup processes.

Scaling can be minimized by pretreatment processes like ion exchange, chemical treatment like lime softening etc. but

these incur higher costs. In some cases, acidification is practiced to remove insoluble carbonates and sulfates and most

commonly Hydrochloric Acid is used. Recently, the popular choice of RO scale treatment is the use of Antiscalants.

Reverse Osmosis Antiscalants are specialized chemical formulations added to the untreated feed water to increase the

solubility of sparingly soluble salts that cause scaling. They mostly comprise of acrylates and phosphonates that greatly

inhibit carbonate and sulfate precipitation. Since they offer an online scale protection advantage, RO Antiscalants have

become an essential part of operations involving reverse osmosis systems. Such systems avoid mineral scaling and

need less frequent cleaning, show greater efficacy with high permeate quality, decreased water and energy

consumptions and longer operation life.

Nalco PermaTreat PC-191 is an RO Membrane Antiscalant manufactured by Nalco Company. It is a highly effective scale

inhibitor engineered specifically for RO systems. It is suitable for treating brackish, highly saline and effluent feed water

in RO filtration, Nanofiltration and Ultrafiltration systems. It is compatible with all types of RO membranes and can

extend membrane life thus cutting down operating and maintenance costs.

Nalco PermaTreat PC-191’s characteristics can be ideally summarized as:

Effective against scales of calcium, strontium, barium salts of carbonate, sulfate and oxide origin

Zero scaling in system upto 2.6 LSI

Cleans by dispersing particulate fouling

Effective even at low feed water pH upto 5.9

Can be fed directly or as diluted solution in system

Prevents formation of Iron scales

Nalco PermaTreat PC-191 helps resolve all scaling issues in RO Filtration systems and at all instances, the costs incurred

are lower than would be for Ion exchange hardness removal methods.