Boron removal efficiency in small seawater Reverse Osmosis systems

Small single-pass desalination seawater Reverse Osmosis (SWRO) plants may be a solution to freshwater demand in North African countries. In the plant design, the selection of commercial SWRO membranes plays an important role in efficiency, according to the feed and product water qualities. Although the SWRO specific energy consumption has been the main parameter employed to describe the SWRO performance, other parameters such as the salt and boron rejection are of major importance. Therefore, this work analyses the salt and boron removal ability of commercial composite-polyamide membranes to comply with the European Union water normative and the World Health Organization guideline values. The salt rejection and the specific energy consumption are evaluated together to study the relation between these parameters. The analysis of 14 different commercial membranes shows that it is possible to obtain high boron rejection with the best membranes in small single-pass SWRO, at the expense of consuming about 12% more energy.