Boron removal from produced water by facilitated ion transfer Original Research Article

This work aims to develop a novel technology to treat produced water with the intent to reuse it for crop irrigation. The concentration of boron in produced water is relatively high — 4–5 ppm, which gives rise to poisoning of the plants if used for irrigation. Therefore, boron concentration must be reduced to safe levels between 0.3 and 0.5 ppm. A process based on liquid-liquid electrochemistry has been investigated to transfer selectively borate anions present in produced water to an immiscible phase. Experiments have been carried out at laboratory scale under stationary conditions in an ITIES cell (Interface between Two Immiscible Electrolytic Solutions) to determine the suitability of borate receptors, which facilitate transfer from the aqueous phase to the immiscible phase. These measurements allow the determination of the equilibrium conditions for the system and important parameters such as Gibbs energy of transfer for the borate anion. Simulations have been carried out using a finite element method to validate experimental results. The simulations and experimental results are used as a basis for further model development in both static and continuous operation regimes.