Contaminants in Polyelectrolytes Used in Water Treatment

Abstract

For approximately 30 years, the US Public Health Service and the US Environmental Protection Agency (USEPA) offered advisory opinions on the potential health effects of polyelectrolyte coagulant products used in drinking water treatment. In April 1990, the USEPA transferred this responsibility to a consortium of organizations led by the National Sanitation Foundation. Although more than 1,000 polyelectrolyte products were accepted for use by the USEPA, evidence suggests that probably fewer than 10 to 15 different types of polymer compounds are represented. Contaminants such as epichlorohydrin and acrylamide, which are of significant health concern, are associated with these product formulations.

Online Multi-Stage Membrane Filtration of Synthetic Polydispersed Water-Soluble Polymers With Uv Visible Absorption as a Mode for Their Detection

“…245, 230, and 220 nm in the interval 0.1 -4.0 mg/mL, 0.2 -3.0 mg/mL and 0.2 -6.0 mg/mL for samples 1, 2, and 3 respectively. The equations of calibration graphs and regression coefficients (R) for sample number 1, 2, and 3 are: [8][9][10]. We use the combination of MF and GPC to provide more complete information about the molecular weight distribution of the obtained fractions.…”

“…The normally used anionic and non-ionic polymers are low toxic, while cationic types are more toxic, especially for aquatic organisms [5,6]. The health significance of possible contaminants has been reviewed in detail [7,8]. Generally, the monomers are more toxic than other polymers [6].…”

Flocculation of montmorillonite by some hydrophobically modified polycations containing quaternary ammonium salt groups in the backbone

“…Among the synthetic flocculants, polycations primarily account for the fast rise in worldwide consumption. [1][2][3] The chain flexibility, the molecular weight, and the charge density are the main factors determining the application of the cationic polymers in one of the following fields: treatment of drinking water; removal of coal, biological mashes, or waste dyes from industrial wastewaters; paper processing and, related with this, the concentration or thickening of sludges. 4 -8 The combination of polycations with polyanions in dif-ferent ways resulted in a new type of flocculation, dual flocculation.…”

Application of Polyelectrolyte in Turbidity Removal from Surface Water

“…The usage of polymers for water treatment processes are adopted since 1980 [5]. Cationic polymers are used as primary coagulants, whereas nonionic and anionic polymers are used as coagulant aids mostly [6,7]. The advantages of polymers over mineral coagulants are: more than 50% reduction in sludge volume, lower water content, better dewatering characteristic, no effects on water pH, no increase in total dissolved solids of finished water, no dissolution of any substances in the treated water, which in the case of mineral coagulants the dissolution of Al and Fe happens and shorter settling time [8].…”

“…The advantages of polymers over mineral coagulants are: more than 50% reduction in sludge volume, lower water content, better dewatering characteristic, no effects on water pH, no increase in total dissolved solids of finished water, no dissolution of any substances in the treated water, which in the case of mineral coagulants the dissolution of Al and Fe happens and shorter settling time [8]. It has been reported that in U.S. more than half of the water treatment plants have employed one or more polyelectrolyte [6]. In some researches, there have been shown that cationic polyelectrolyte are very applicable for the reduction of THM S precursors [9,10].…”