Novel boron specific copolymers with quaternary amine segments for efficient boron removal via PEUF

In this study, a copolymer, poly (vinyl amino-N, N′-bis-propane diol-co-DADMAC) (GPVA-co-DADMAC) was synthesized in three comonomer ratios (2%, 5% and 10%) and efficiently exploited for boron removal via polymer enhanced ultrafiltration (PEUF). Boron concentration could be reduced from 10ppm down to 0.8ppm by the employment of novel copolymer in continuous PEUF at pH 9 and boron-to-polymer mass ratio (loading) of 0.001. Polymer precipitation was not observed even after complexation with boron. Boron retention was found to be highly pH dependent and boron concentration dependent at constant loading. Hence, efficient polymer regeneration can be expected due to high pH and concentration dependency of boron complexation. Moreover, permeate flux was not affected by the polymer concentration in the conditions studied (polymer concentration ≤10g/L; pressure drop: 2bar). Dynamic and static light scattering measurements showed that gyration radius of the polymers rises by dilution or by increasing pH of the solutions. Furthermore, a two-step equilibrium model was correlated with the experimental boron retention data. Having high boron binding affinity, hydrolytic stability and efficiency in boron removal, the synthesized copolymers possessing DADMAC segments seemed to be attractive and useful for large scale water treatment with PEUF systems. ► Chelating copolymers were synthesized for boron removal via PEUF process. ► Effects of various parameters on polymer conformation were studied. ► Effects of pH, loading and comonomer ratio on boron retention were investigated. ► Experimental boron retention values were correlated with a complexation model. ► The presented copolymers seem promising for use in real boron removal applications.