Theoretical and experimental investigation of boron rejection by forward osmosis membrane

Abstract

This study focused on the investigation of the boron rejection from model solutions using a forward osmosis (FO) membrane. A laboratory-scale plate-and-frame membrane module and stirred cell device were used for the experiments. The boron rejection were examined in both reverse osmosis and FO operating modes. A theoretical model based on the film theory was applied for the analysis of boron rejection. Experimental results indicated that the boron rejection by FO membranes was improved by raising pH, suggesting that the removal of boron is done either by charge repulsion or by size exclusion. FO treatment of feedwater containing a high proportion of boric acid led to relatively high concentration of boron in the permeate water. This implies that FO membrane may require another process to attain sufficient rejection to boron. The model calculation was also compared with the experimental data for better understanding of boron rejection in FO membrane systems.

Keywords:

• Forward osmosis
• Boron
• Seawater desalination
• Rejection
• Modeling

Acknowledgment

This research was supported by a grant(code 15IFIP-B065893-03) from Industrial Facilities & Infrastructure Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.

Notes

Presented at 2015 Academic Workshop for Desalination Technology held in the Institute for Far Eastern Studies Seoul, Korea, 23 October 2015