Polymers in Water Treatment

The extensive industrial and commercial utilization of water-soluble polymers (polyelectrolytes) in water treatment has been developed based on the charge along the polymer chains and the resultant water solubility. The use of water-soluble polymers in water treatment has been investigated by several authors [5-26] in the recovery of metals radioactive isotopes, heavy metals, and harmful inorganic residues. This allows recycling water in the industrial processes and so greatly saves... 

Kumar, K., and Verma, M. (2007). Functionalization of psyllium with methacrylic acid through grafting and network formation for use of polymers in water treatment. /. Appl. Polym. Sci. 103,1025-1034. 

BF Goodrich Company. The Role of Polymers in Water Treatment Applications and Criteria for Comparing Alternatives. Paper presented at 6th Convention, Association of Water Technologies, Inc., November 1993. 

Jackson LA. Applications of cationic polymers in water treatment In Amjad Z, editor. Science and Technology of Industrial Water Treatment. Boca Raton CRC Press 2010. p 465 79. 

Cationic monomers are used to enhance adsorption on waste soHds and faciHtate flocculation (31). One of the first used in water treatment processes (10) is obtained by the cyclization of dimethyldiallylammonium chloride in 60—70 wt % aqueous solution (43) (see Water). Another cationic water-soluble polymer, poly(dimethylarnine-fi9-epichlorohydrin) (11), prepared by the step-growth... 

The protonated form of poly(vinyl amine) (PVAm—HCl) has two advantages over many cationic polymers high cationic charge densities are possible and the pendent primary amines have high reactivity. It has been appHed in water treatment, paper making, and textiles (qv). The protonated forms modified with low molecular weight aldehydes are usehil as fines and filler retention agents and are in use with recycled fibers. As with all new products, unexpected appHcations, such as in clear antiperspirants, have been found. It is usehil in many metal complexation appHcations (49). 

Among the basic fields of applications, the major use of acrylamide polymers is liquid-solid separation in water treatment and waste treatment. Smaller quantities are used in the manufacturing of paper and in the processing of minerals in mining. Relatively nonlarge quantities are use as additives for enhanced oil recovery. 

Several cleaning methods are used to remove the densified gel layer of retained material from the membrane surface. Alkaline solutions followed by hot detergent solutions are indicated for organic polymer colloids and gelatinous materials fouling. Ferrous deposits, t3 pical in water treatments, are usually removed with a citric or hydrochloric wash. [35]. 

Acrylic textile fibers are primarily polymers of acrylonitrile. It is copolymerized with styrene and butadiene to make moldable plastics known as SA and ABS resins, respectively. Solutia and others electrolytically dimerize it to adiponitrile, a compound used to make a nylon intermediate. Reaction with water produces a chemical (acrylamide), which is an intermediate for the production of polyacrylamide used in water treatment and oil recovery. 

The study was an attempt to correlate polymer structure to its activity in water treatment applications. Copolymers of acrylic acid with N-(hydroxyraethyl)-, N-(2-hydroxyethy1)-, and N-(2-hydroxypropyl) acrylamide were prepared. 

The copolymers in this study were all in a 3 1 mole ratio of acrylic acid with N-(hydroxyalkyl)acrylamide. Different mole ratios and other molecular weight ranges may have different testing results. However, by continuing this kind of systematic study, we may be able to understand more about the relationship between polymer structure and its activity in water treatment. Hopefully, it can facilitate in choosing or synthesizing a specific polymer for the desired application. 

Acrylic acid and its salts are raw materials for an important range of esters, including methyl, ethyl, butyl, and 2-ethylhexyl acrylates. The acid and its esters are used in polyacrylic acid and salts (32%, including superabsorbent polymers, detergents, water treatment chemicals, and dispersants), surface coatings (18%), adhesives and sealants (15%), textiles and non-wovens (12%), plastic modifiers (5%), and paper coating (3%). 

The protonated form of poly(vinyl amine) (PVAm-HCl) has two advantages over many canonic polymers high cationic charge densities are possible and the pendent primary amines have high reactivity. It has been applied in water treatment, paper making, and textiles. 

Ware AJ (1996) The use of soluble organic polymers in waste treatment. Water Sci Technol 34 117... 

Ever since the discovery of the steam engine, the precipitation of insoluble calcium salts in boilers and pipes has been causing severe problems. Thus, the discovery that low concentrations of phosphoric, pyrophosphoric or bisphosphonic acids can prevent scale had enormous industrial importance. This information, combined with the characteristic ability of BPs to chelate virtually every heavy metal, laid the basis for their wide industrial importance [4], As a result, bisphosphonates are in current use in a wide variety of industrial areas, as scale inhibitors, for the treatment of metal and other surfaces, in water treatment, in the textile industry, in the detergent and cosmetic industry, in the polymer industry, and several others [4],... 

Polymeric macromoleculcs of types V-VII are needed for applications requiring enhanced molecular siite (see also Chap. III). Thus, linear polymers of type V are prepared by Mannich polymerization or from bis-Mannich bases by exchange reaction, for example, with bis-thiols, as in the case of poly(ketosulfide) 501, which is useful as a high-molecular-weight antioxidant in the processing of plastics.Macromolecules of type VI are generated by the functionalization of polymers, as shown by 502, which is obtained by aminomethylation of polyacrylamide and used as flocculant in water treatment." - ... 

The polymerization of acrylamide (AM) and the copolymerization of acrylamide-sodium acrylate in inverse microemulsions have been studied extensively by Candau [10,11,13-15], Barton [16, 17], and Capek [18-20]. One of the major uses for these inverse microlatexes is in enhanced oil recovery processes [21]. Water-soluble polymers for high molecular weights are also used as flocculants in water treatments, as thickeners in paints, and retention aids in papermaking. 

They can also be used as flocculants for many substrates, such as cellulose fibers and in water treatment. The water-in-oil microlatices are destabilized and inverted by adding excess water, which releases the water-swollen polymer particle to the water phase. The efficiency of the usual polymers is however altered by rapid temperature changes, especially in winter, which favor the aggregation of the fine polymer particles, thus strongly decreasing their flocculation effect. The polyacrylamides prepared by... 

C. Calmon, Recent developments in water treatment by ion exchange, Reactive Polymers 4, 131-146 (1986). 

One of the prime environmental objectives is the removal of suspended contaminants from water and waste streams. Water turbidity in nature is the result of colloidal clay dispersion and the color is from decayed wood and leaves (tannins and lignins) and organic soil matter. In addition to these contaminants, there are viruses, algae, bacteria, metal oxides, oils and other pollutants. In recent years, synthetic organic polyelectrolyes, in particular the cationic polymers, have been used very effectively in water treatment (3). These polyelectrolytes are high... 

These polymers are mostly applied in the paper industry for wet-strength papers usable in neutral of alkaline systems instead of the urea-formaldehyde resins requiring acid conditions for crosslinking. PolyEI increases retention of dyes, pigments and fillers. PolyEI is known as a powerful flocculant used in the clarification of fruit juices and in water treatment. It removes effectively clays, colloidal acids, pectines and tannines from water. Commercially available polyEI have molecular weights in the range Mn = 600 to 100000 60). 

---