Boron removal from brackish water by reverse osmosis and nanofiltration membranes: application of Spiegler-Kedem model and optimization

Drinking water should contain certain chemicals only in limited quantities. Boron, one of these chemicals which is considered as a threatening compound and is difficult to eliminate from water. The purpose of the research is to study the major role of reverse osmosis (RO) and nanofiltration (NF) process which can contribute to the removal of this inorganic element from brackish water. For this reason, two RO and two NF membranes have been used to reduce boron and total salinity of brackish water. Since boron is a problematic compound, its elimination would also not be easy. To optimize these removal rates, two solutions based on the change of the chemical state of boron in water, either by varying the pH solution or by a complexation reaction, have been proposed in this work. Obtained results show that for both solutions, the boron removal percentage has clearly improved and reached 95% for the first case and 70% for the second. It is worth noting that the Spiegler-Kedem model was applied to fit the found experimental results.