Imino-bis-propane diol functional polymer for efficient boron removal from aqueous solutions via continuous PEUF process

Boron contamination is an environmentally serious problem especially due to its hazards on plants. In this work, newly synthesized poly (vinyl amino-N, N′-bis-propane diol) (GPVA) is presented as an excellent chelating polymer for boron removal. Boron concentration could be reduced from 10 ppm down to 0.4 ppm via total recycle Polymer Enhanced Ultrafiltration (PEUF). Experiments revealed that the polymer shows the highest PEUF boron rejections (96% at pH 9.0) reported so far, without precipitation in a wide concentration range. Detailed investigations such as effect of pH, loading (boron-to-polymer mass ratio) and polymer concentration showed that, the boron binding is highly pH dependent and increases with boron concentration at constant loading. Furthermore, permeate flux was found as nearly independent from polymer concentration up to 10 g/L at 200 kPa pressure drop. In addition, gyration radius of the polymer in solution increases while increasing pH and polymer concentration in the presence of boron as inferred from Dynamic and Static Light Scattering measurements. Regarding with high efficiency and hydrolytic stability of GPVA, its use in combination with PEUF would be of interest for large scale and long term use in boron removal.

► A novel polymer was synthesized for use in trace boron removal via PEUF process.
► Effect of pH, concentration and presence of boron on polymer radius was investigated.
► Effect of pH, loading, polymer molecular weight on boron retention was investigated.
► The proposed boron removal scheme seems satisfactory for real applications.