Elimination de la dureté et des sulfates contenus dans les eaux par nanofiltration

This study focuses on an hybrid process which couples ultrafiltration and stripping. The aim is to treat spring water to disinfect it and to enhance its pH without adding reactants. The first part of the study focused on stripping in a batch stirred reactor without UF. Air was chosen as the stripping gas, and the influence of the air flow rate on the water quality was studied for the stirred reactor and then for the hybrid process. Benefits of gas sparging have previously been pointed out in terms of fouling removal. This study demonstrates that gas sparging can be used to enhance the pH by removing a dissolved compound by gas stripping. Very good mass transfer coefficients are obtained in comparison with conventional systems like the batch stirred reactor or bubble columns.