Industrial Water Treatment and Flocculants

The most broadly used material for modern industrial processes is water. It is used to manufacture many industrial products, as well as cool the equipment used to manufacture said products. As such, water quality plays a critical role in almost any manufacturing process imaginable. As industrial manufacturing accounts for one of the biggest water users on the planet, water optimization, re-use, and disposal are critical topics for this vital resource.

Water Treatment Flocculants

Flocculants are a key component for any water treatment solution. Treatment systems often require a flocculant prior to disinfection and filtration. These chemicals, typically organic polymers, cause agglomeration of fine colloidal materials that would otherwise be too small to be captured by a filter. As a result, they can be separated and removed from the water via filtration for the treatment system. Flocculants are especially important in the pulp & paper, oil & gas, and mining industries.
 

POLYOX™ Highly Efficient Flocculation

POLYOX™ Water Soluble Resins are nonionic polyethylene oxide polymers that are effective water treatment flocculants. High molecular weight grades of POLYOX™ easily adsorb onto colloidal materials such as silicas and clays. This promotes the agglomeration of high strength flocs that can be efficiently separated from water via filtration. POLYOX™ also exhibits a high affinity for the pulps and fillers used in papermaking processes, making it an excellent retention aid.

How POLYOX™ Provides Flocculation

POLYOX™ adsorbs to the surface of silica particles via hydrogen bonds made between the ether oxygen of the polyethylene oxide and the hydroxyl groups on hydrated silica particles. As POLYOX™ is hydrophilic, a competition emerges between hydrogen bonding with water in bulk and the surface hydrated layer of the oxide minerals. This competition results in tails and loops forming on the surface of the silica particles. These then hydrogen bond with other suspended solids, causing the development of agglomerations or "flocs" that are large enough to be captured by a filter.

 

Flocculation Performance

The flocculation performance of POLYOX™ WSR 308 on suspended silica particles was demonstrated by evaluating the turbidity of a colloidal silica suspension, where varying rates of POLYOX™ WSR 308 were added. The following graph shows the turbidity of silica suspension as a function of POLYOX™ WSR 308 concentration.

As shown by the graph above, POLYOX™ WSR 308 begins flocculation at 0.5 ppm and has a maximum effect at 2 ppm. This addition rate is much lower than the typical 10 ppm needed for other common flocculants.

POLYOX™ WSR 308 was also compared for performance with commercially available cationic, anionic, and nonionic polyacrylamides (PAMS) that are used in water treatment applications. The turbidity of a silica suspension was measured to determine the effectiveness of the flocculants. The following graph shows the performance of POLYOX™ WSR 308 (2 ppm) versus polyacrylamides (10 ppm),

This indicates that POLYOX™ WSR 308 performs much better than polyacrylamides. Not only did POLYOX™ WSR 308 provide significantly greater reduction in turbidity, but it did so at only 2 ppm as compared to 10 ppm for the PAMS.

Summary

The investigation shown above illustrates that POLYOX™ polymers are a more efficient in providing flocculation than other common organic polymers like polyacrylamides. Clarification of water containing high levels of siliceous contaminants can be dramatically enhanced by using POLYOX™ polymers. Since relatively less POLYOX™ is necessary to be effective, the overall cost of the water treatment process can also be reduced. Due to the nonionic nature of POLYOX™ and the mechanism in which it flocculates, POLYOX™ polymers may also be blended with other commercial flocculants to further enhance existing systems.