Seawater desalination pre-treatment process in an electrochemical filtration system to increase pH

Abstract

This paper proposes an alternative method using electrochemical filtration system with an ultrafiltration (UF) membrane in the pre-treatment process of desalination to bring up pH values for seawater reverse osmosis (SWRO) to allow sufficient boron to be removed to desired level in one pass SWRO process, with a possibility to eliminate the post-treatment low pressure reverse osmosis system at an overall lower energy cost without input of additional chemicals. An electrochemical cell can be integrated into the UF process where a piece of UF membrane is placed between the two electrodes of the electrochemical cell. The electrochemical cell enables a direct control of the pH in the solution by adjusting the potential difference of the cell. This integration allows similar rejection capabilities as the current pre-treatment system while able to control pH value of the water. This study aims to introduce the use of electrochemical system in seawater desalination pre-treatment process to make desalination more energy efficient and economically viable.