The concept of a system for electrodialytic boron removal into alkaline concentrate

The objective of this work was to investigate the effectiveness of boron transport into the alkaline concentrate during the course of ED and propose a technical solution for it. The effect of concentrate boron content and pH as well as voltage drop was investigated in a batch mode. The obtained results were evaluated statistically and the mathematical model for the boron flux was revealed. It was found that the boron flux was determined by sole boric acid diffusion. The obtained results were applied to propose a cascade system for ED boron removal and its concentration. A cascade of three ED units with an effective membrane length equal to 100 cm was designed. The cost of the removal of boron from 75 mg/L to 0.8 mg/L with simultaneous boron concentration to 5000 mg/L was estimated at $0.22/m3.

► Model for boron transport into the alkaline ED concentrate
► The effect of concentrate boron content, pH, and voltage drop investigation in a batch mode
► Boron flux is determined by sole boric acid diffusion.
► A cascade system for ED boron removal and its concentration
► Estimation of the cost of removal of boron and its simultaneous concentration